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Flashcards in CARDIOVASCULAR- Physiology Deck (366):
1

Which ia the formula to calculate Cardiac output?

Stroke volume X heart rate

2

Using Fick principle how do you calculate Cardiac output?

CO= Rate of O2 consumption
---------------------------------------------------------
arterial O2 content- venous O2 content

3

What is the mean arterial Pressure?

Cardiac output X Total peripheral resistance

4

Formula to calculate Mean arterial pressure

MAP= 2/3 diastolic pressure+ 1/3 systolic pressure

5

How do you calculate Pulse pressure?

Pulse pressure= Systolic pressure- diastolic pressure

6

What is the pulse pressure?

Is proportional to Stroke volume, inversely proportional to arterial compliance

7

In order to calculate Stroke volume we need this formula

SV= End Dyastolic Volume- End systolic Volume

8

During early stege of excercise how is Cardiac output maintan?

↑ Heart rate and ↑ Stroke volume

9

During late stages of excercise how is the Cardiac output affected?

↑ Heart rate only (Stroke volume plateu)

10

How is Diastole affected with ↑ Heart rate?

Diastole is prefetentially shortened with ↑ Heart rate

11

How is Cardiac Output affectedif Diastole is shortened with ↑ Heart Rate?

Less filling time → ↓ CO (eg Ventricular tachycardia)

12

When is Pulse pressure increased?

In hyperthyrodism, aortic regurgitation, arteriosclerosis, obstructive apnea (sympathetic tone), exercise (transient)

13

In these situation pulse pressure is decreased

Aortic stenosis, cardiogenic shock, cardiac tamponade, and advanced hear failure

14

Who affects Stroke volume?

By Contractility, Afterload, Preload

15

When does Stroke volume increases?

↑ contractility, ↑ preload or ↓ afterload

16

When do Contractility and Stroke volume (SV) increase?

Cathecholamines
↑ increased intracellular Ca2+
↓ extracellular Na+ (↓ activity of Na+/Ca2+ exchanger)
Digitalis

17

How digitalis increase contractility?

Blocks Na+/ K+ pump → ↑ intracellular Na+ → ↓ Na+/Ca2+ exchanger → ↑ intracellular Ca2+

18

Explain the mechanism of how cathecolamins increase contractility

↑ activity of Ca2+ pump in sarcoplasmic reticulum

19

In these situations Contractility and Stroke volume is decreased

β 1 blockade (↓cAMP)
Heart failure with systolic dysfunction
Acidosis
Hypoxia/ Hypercapnea (↓ PO2/ ↑ PCO2)
Non dihydropyridine Ca2+ blockers

20

These are normal situations that increase Stroke volume

Anxiety, excercise, pregnancy

21

How does a failling heart affects Stroke Volume?

↓ Stroke Volume (both systolic and diastolic dysfunction)

22

Which situation increase Myocardial O2 demand?

↑ afterload
↑ contractility
↑ Heart rate
↑ ventricular diameter (↑ wall tension)

23

Which measured is approximated to Preload?

Ventricular End dyastolic Volume (EDV)

24

Preload depends on this factors

Venous tone and circulating blood volume

25

What decreases preload?

Venodilators (nitroglicerin)

26

Which measured is approximated to Afterload?

By MAP (Mean Arterial pressure)

27

What does Laplace's law states related to Afterload?

Relation of Left Ventricle size and afterload

28

Laplace's law formula

Wall tension = pressute X radius
----------------------------
2 X wall thickness

29

Law related to After load

Laplace's Law

30

What is the result of ↑ After load?

LV compensates for ↑ Afterload by thickening (hypertrophy) to ↓ wall tension

31

This drug Decreases just Afterload?

Vasodilators (hydralazine) ↓ Afterload (arterial)

32

These drugs decrease both Atferload and Preload

ACE inhibitors and ARBs

33

Which chronic situation can lead to Left ventricle hypertrophy?

Chronic hypetension (↑ MAP)

34

Formula to calculate Ejection Fraction

SV EDV- ESV
EF= ------- = ----------------
EDV EDV

35

What does Left ejection means?

Index of ventricular contractility

36

Which is the normal value of Ejection Fraction?

> 55 %

37

When is Ejection Fraction decreased?

In systolic heart failure

38

How is Ejection fraction in dyastolic heart failure?

Normal

39

Force of contraction is proportional to...

End diastolic length of cardiac muscle fiber

40

What is End diastolic length of cardiac muscle fiber?

Preload

41

When is Contractility decreased?

Loss of myocardium (eg. MI), β blocker, calcium channel blockers, dilated cardiomyopathy

42

Which are the parameters measured in Starling curve?

Stroke Volume (or Cardiac Output) compared to Ventricular End diatolic Volume (Preload)

43

In which situation is Starling curve above normal range

Excercise

44

When is Starling curve below normal range?

CHF+ digoxin
CHF

45

What is ΔP?

Changes in pressure (pressure gradient)

46

What is Q?

Flow

47

Meaning of R

Resistance

48

Formula to calculate Pressure gradient

Pressure gradient (ΔP) = Flow (Q) X Resistance (R)
ΔP = Q X R

49

Which other formula is similar to ΔP = Q X R?

Ohm's law: ΔV = IR

50

In order to calculate Resistance what is needed?

driving pressure (ΔP) 8 n (viscosity) X length
R= -------------------------------- = -----------------------------------
flow (Q) πr4

51

How is Total resistance of vessels in series calculated?

TR= R1+ R2+ R3.....

52

For Total resistance of vessels in parallel this is the Formula

1 1 1 1
---- = --- + --- + --- ....
TR R1 R2 R3

53

On what mostly depends the viscosity?

On Hematocrit

54

When is Viscosity increased?

Polycythemia
Hyperproteinemic states (multiple myeloma)
Hereditary spherocytosis

55

When is viscosity decreased?

Anemia

56

How does pressure gradient drives flow?

From high pressure to low pressure

57

What is directly proportional to resistance?

Directly proportional to viscosity and vessel

58

Resistance is inversely proportional to....

the radius to the 4th power

59

They regulate capillary flow

Arterioles account for most of Total Peripheral Resistance

60

What happens in inotropy?

Changes in contractility → altered Cardiac Output for a given Right Atrium pressure (preolad)

61

They are inotropy positive

Catecholamines, digoxin

62

Examples of inotropy negative

Uncompensated heart failure, narcotic overdose

63

What causes Venous return changes?

Altered Rigth Atrium pressure for a given Cardiac output. Mean systemic pressure changes with volume/ venous tone.

64

In venous return, when does the mean systemic pressure changes?

With volume/ venous tone

65

Example of Positive venous return

Fluid infusion, sympathetic activity

66

Name situation that negatively stimulates venous return

Acute hemorrhage, spinal anesthesia

67

What causes Total peripheral resistance changes?

Altered Cardiac Output at a given Rigth Atrial pressure; however, mean systemic pressure is unchanged

68

What causes positive total peripheral resistance?

Vasopresors

69

In this situation exist negative total peripheral resistance

Exercise, AV shunt

70

How are cardiac and vascular functions affected by excersice?

Reinforcing:
↑ inotropy
↓ Total peripheral resistance
To maximize Cardiac Output

71

How are cardiac and vascular functions affected by heart?

↓ inotropy
Fluid retention to ↑preload to maintain Cardiac Output

72

Which are the phases of Pressure volume loops and cardiac cycle?

1) Isovolumetric contraction
2) Systolic ejection
3) Isovolumetric relaxation
4) Rapid filling
5) Reduced filling

73

When does the isovolumetric contraction occurs?

Period between mitral valve closing and aortic valve opening

74

When is the period of highest O2 consumption?

During isovolumetric contraction

75

Period of Systolic ejection

Period between aortic valve opening and closing

76

Period between aortic valve closing and mitral valve opening

Isovolumetric relaxation

77

Period just after mitral valve opening

Rapid Filling

78

Reduced Filling

Period just before mitral valve closing

79

What does S1 means?

Mitral and tricuspide valve closure

80

Where is the loudest area to hear S1?

Mitral area

81

What is the meaning of S2?

Aortic and pulmonary valve closure

82

Where is better heard S2?

Left Sternal border

83

What does S3 means?

In early diastole during rapid ventricular filling phase

84

Which situations are associated to S3?

↑ Filling pressures (eg. mitral regurgitation, CHF) and common in dilated ventricles

85

When is S3 consider normally?

Normal in children and pregnant women

86

Alternative name for S4?

Atrial kick

87

When is S4 heard?

In late diastole

88

What does S4 means?

High atrial pressure

89

If we heard a S4 what should we think?

Associated with ventricular hypertrophy. Left atrium must push against stiff LV wall

90

Which are the four waves in Jugular venous pulse?

a, c, x, v, y

91

What does a wave in Jugular venous pulse means?

Atrial contraction

92

Which is the meaning of c wave in Jugular venous pulse?

RV contraction (closed tricuspid valve bulging into atrium)

93

What does x descent in Jugular venous pulse means?

Atrial relaxation and downward displacement of closed tricuspid valve during ventricular contraction

94

When is x descent absent?

In tricuspid valve

95

v wave in Jugular venous pulse means

↑ right atrial pressure due to filling against closed tricuspid valve

96

Meaning of y descent wave

Blood flow from Right Atrium to Right Ventricle

97

What happens in normal heart splitting sound?

Inspiration → drop in intrathoracic pressure→ ↑ venous return to the RV→ ↑ RV stroke volume → ↑ RV ejection time→ delayed closure of pulmonary valve

98

What else happens during insipiration?

↓ pulmonary impedance (↑ capacity of the pulmonary circulation)

99

What contributes to delayed closure of pulmonic valve?

↓ pulmonary impedance (↑ capacity of the pulmonary circulation)

100

How is represented Normal splitting?

Expiration I I I
S1 A2 P2
Inspiration I I I

101

When is heard the wide splitting of Heart sounds?

Seen in conditions that delayed RV emptying:
Pulmonic stenosis
Right bundle branch block

102

What does delay in RV causes?

Delayed pulmonic sound (regardless of breath)

103

How is wide splitting heard?

An exaggeration of normal splitting

104

Represent the wide splitting

Expiration I I I
S1 A2 P2
Inspiration I I I

105

When is Fixed splitting seen?

Atrial Septal Defect

106

Which are the repercussions of Atrial Septal Defect?

Atrial Septal Defect → left to right shunt → ↑ Ra and RV volumes → ↑ flow through pulmonic valve such that, regardless of breath, pulmonic closure is greatly delayed

107

How is the fixed splitting pattern?

Expiration I I I
S1 A2 P2
Inspiration I I I

108

When is paradoxical splitting heard?

In conditions that delay LV emptying

109

Which situations delay LV empting?

Aortic stenosis, left bundle branch block

110

What is the difference of a normal splitting and paradoxical spliting?

Normal order of valve closure is reversed so that P2 sounds occurs before delayed A2 sound

111

This is the reason why is a paradoxical splitting

On insporation, P2 close later and moves closer to A2, thereby "paradoxycally" eliminating the split

112

Schematically how is Paradoxical splitting?

Expiration I I I
S1 P2 A2
Inspiration I II

113

What can be heard in Aortic area?

Systolic murmur

114

Systolic murmurs in Aortic area?

Aortic stenosis
Flow murmur
Aortic valve sclerosis

115

What can be heard in left sternal border?

Diastolic and Systolic murmurs

116

You might identify these diastolic murmur pathologies in the left sternal border

Airtic regurgitation
Pulmonic valve regurgitation

117

You might identify these systolic murmur pathology in the left sternal border

Hypertrophic cardiomyopathy

118

what can be heard in Pulmonic area?

Systolic ejection murmur

119

What can a systolic ejection murmur in pulmonic area mean?

Pulmonic stenosis
Flow murmur (physiologic murmur)

120

This is what can be heard in Tricuspid area

Pansystolic murmur
Diastolic murmur

121

Pansystolic murmur in Tricuspid area can mean...

Tricuspid regurgitation
Ventricular Septal defect

122

Diastolic murmur in Tricuspid area can mean...

Tricuspid stenosis
Atrial septal defect

123

Mitral area sounds can be classified as

Systolic and Dyastolic murmurs

124

Systolic murmur in mitral area means...

Mitral regurgitation

125

Diastolic murmur in Mitral area means...

Mitral stenosis

126

How can a Atrial Septal Defect be presented?

Pulmonary flow murmur (↑ flow across tricuspid); blood flow across the actual ASD does not cause a murmur because there is no pressure gradient

127

How the murmur of Atrial septal defect can evolve?

The murmur later progresses to a louder diastolic murmur of pulmonic regurgitation from dilation of the pulmonary artery

128

During inspiration how are heart sounds modified?

↑ intensity of right heart sounds

129

What is the effect of Hand grip maneuver?

↑ systemic vascular resistance

130

What can be heard with Hand grip maneuver?

↑ intensity of MR, AR, VSD murmurs
↓ intensity of AS, hypertrophic cadiomyopathy murmurs

131

How can Had grip maneuver affect Mitral valve prolapse sounds?

↑ murmur intensity, later onset of click/murmur

132

When is better apreciated Valsalva maneuver?

phase II

133

What is the effect of Standing in systemic circulation?

↓ venous return

134

If Valsalva maneuver or Standing is realizaed Which murmurs are affected?

↓ intensity of most murmurs (including AS)

135

Which murmurs are ↑ with Valsalva maneuver or Standing?

Hypertrophic cardiomyopathy murmur

136

How can Valsalva maneuver or Standing affect Mitral valve prolapse sounds?

↓ murmur intensity, earlier onset of click/murmur

137

Which are the effects of Rapid squating?

↑ venous return, ↑ preload, afterload with prolongued squating

138

What murmur is ↓ in intensity with Rapid squating?

Hypertrophic cardiomyopathy murmur

139

Which murmur is ↑ in intensity with Rapid squating?

AS (aortic stenosis)murmur

140

How can Rapid squating affect Mitral valve prolapse sounds?

↑ murmur intensity, later onset of click/murmur

141

What pathologies does Systolic heart sounds include?

Aortic/ pulmonic stenosis, Mitral/ tricuspid regurgitation, ventricular septal defect

142

These pathologies are included in Diastolic heart sounds

Aortic/ pulmonic regurgitation, mitral/tricuspid stenosis

143

How is Mitral/Tricuspid regurgitation heard?

Holosystolic, high pitched blowing murmur

144

Where is better heard mitral?

Loudest at apex and radiates toward axilla

145

What enchance Mitral sounds?

By maneuvers that ↑ Total peripheral resistance

146

Which are common reasons of Mitral regurgitation?

Ischemic heart disease, Mitral Valve prolapse, Left ventricle dilation

147

Where is Tricuspid sound better heard?

Loudest at tricuspid areaand radiates to right sternal border

148

When is Tricupid enhance?

By maneuvers that ↑ Rigth Atrial return (eg inspiration)

149

Which is the common cause of Tricuspid Regurgitation?

Right ventricle dilation

150

Which pathology can cause either Mitral Regurgitation of Tricuspid Regurgitation?

Infective Endocarditis

151

This is the murmur caused by Aortic stenosis

Crescendo-decrescendo systolic ejection murmur

152

What happens in Aortic stenosis?

LV>> aortic pressure during systole

153

Where is Aortic Stenosis better heard?

Heart base; radiates to carotids

154

Which pulse is seen in Aortic Stenosis? What does it means?

"Pulsus parvus et tardus"- pulsesare weak with delayed peak

155

Which could be the results if Aortic Stneosis?

Syncope, Angina, Dysnea on exertion

156

These are reasons of Aortic Stenosis

Age related calcific aortic Stenosis or Bicuspid aortic valve

157

What can be heard in Ventricular Septal Defect?

Holosystolic, harsh sounding murmur

158

Where is better heard Ventricular Septal Defect?

Loudest at tricuspid area

159

What accentuates Ventricular Septal Defect murmur?

Hand grip maneuver due to ↑ afterload

160

What is heard in Mitral Valve prolapse?

Late systolic crescendo murmur with midsystolic click

161

Why is Midsystolic click heard in Mitral valve prolapse?

Due to tensing of chordae tendineae

162

Which is the most frequent valvular lession?

Mitral valve prolapse

163

Where is better heard mitral valve prolapse?

Over Apex

164

When is better heard mitral valve prolapse?

Loudest just before S2

165

How is the prognosis of Mitral valve prolapse?

Usually Benign

166

What can Mitral valve prolapse predispose?

Infective endocarditis

167

Which could be the causes of Mitral valve prolapse?

Myxomatous degeneration, rheumatic fever, or chordae rupture

168

What predisposes an earlier apperance of Mitral valve prolapse?

Maneuvers that ↓ venous return (standing or Valsalva)

169

How are Heart murmurs classified?

Systolic
Diastolic
Continuous

170

Name systolic murmur causes

Mitral/ Tricuspid regurgitation
Aortic Stenosis
Ventricular Septal Defect
Mitral Valve prolapse

171

These are Diastolic murmur causes

Aortic regurgitation
Mitral stenosis

172

In this pathology we can heard a Continuous murmur

Patent Ductus Arteriosus

173

What is heard in Aortic regurgitation?

High pitched "blowing" early diastolic decrescendo murmur

174

When Aortic regurgitation is chronic what can be seen?

Wide pulse pressure; can present with bounding pulses and head bobbing

175

These are possible causes of Aortic Regurgitation

Aortic Root dilation
Bicuspid aortic valve
Endocarditis
Rheumatic fever

176

When is aortic regurgitation better heard?

↑ murmur during hand grip

177

What decreases intensity of murmur in Aortic regurgitation?

With Vasodilators

178

In mitral Stenosis what is heard?

Follows opening snap

179

Which is the reason of Opening snap in Mitral Stenosis?

Due to abript half in leaflet mition in diastole, after rapid opening due to fusion at leaflet tips

180

When is Mitral Stenosis heard?

Delayed rumbling late diastolic murmur

181

In mitral Stneosis what correlates with increased severity?

↓ Interval of between S2 and Opening Snap

182

This is what happens in Mitral Stenosis

LA >> LV pressure during diastole

183

Which is the most common reason of Mitral Stenosis?

Secondary to Rheumatic Fever

184

What could be the result of Chronic Mitral Stenosis?

Left Atrial Dilation

185

What enhances Mitral stenosis?

Maneuvers that ↑ Left Atrial return (expiration)

186

What is heard in Patent ductus arteriosus?

Continuous machine-like murmur

187

When is Patent ductus arteriosus murmur better heard?

Loudest at S2

188

Common causes of Patent ductus arteriosus

Congenital Rubella
Prematurity

189

Where is Patent ductus arteriosus murmur better heard?

At left infraclavicular area

190

Where else does Ventricular action potential takes place?

Bundle of His and Purkinje fibers

191

How many phases does Ventricular action potential has?

0, 1, 2, 3, 4

192

What happens in Phase 0 of Ventricular action potential?

Rapid upstroke and depolarization

193

Which channles are open in Ventricular action potential phase 0?

Voltage gated Na+ channels

194

This phase is known as initial repolarization in Ventricular action potential

Phase 1

195

Which channels interact in Phase 1 of Ventricular action potential?

Inactivation of Voltage gated Na+ channels
Voltage gated K+ channels begin to open

196

How is phase 2 of Ventricular action potential known?

Plateau

197

Which channels are affected in Plateau phase of Ventricular action potential?

Ca+ influx through voltage gated Ca2+ channels balances K+ efflux

198

During phase 2 of Ventricular action potential what does Ca2+ influx triggers?

Triggers Ca2+ release from sarcoplasmic reticulum and myocyte contraction

199

Also known as Rapid repolarization phase in Ventricular action potential

Phase 3

200

What happens in Rapid repolarization phase during Ventricular action potential?

Massive K+ efflux due to opening of voltage gated slow K+ channels and closure of gated Ca2+ channels

201

What is phase 4 of Ventricular action potential?

Resting potential

202

Which channels are permeable in Resting potential?

High K+ permeability through K channels

203

Which is the difference in channels between skeletal muscle and Cardiac muscle?

Cardiac Miscle action potential has a plateau, which is due to Ca2+ influx and K+ efflux
Myocite contraction occurs due to Ca2+ induced Ca2+ release from the sarcoplasmic reticulum

204

When are Cardiac nodal cells depolarize?

During Diastole

205

What is the result of cardiac nodal cells depolarization?

Automaticity due to If channels

206

What are If channels?

"Funny current" channels responsible for a slow, mixed Na+/ K+ inward current

207

What other difference do Cardiac cells have from Skeletal muscle cells?

Cardiac Myocytes are electrically coupled to each other by gap junctions

208

From how many mV does Ventricular action potential goes?

More than 0 mV to -85 mV

209

How much time does Efective refractory period last?

200 msec

210

From which phases does Efective refractory period takes place?

From phase 1 to phase 4

211

What is the Efective refractory period?

Is the time when the cardiac cell can't be depolarize

212

Where does Pacemaker action potential occurs?

In the SA and AV nodes

213

What happens in Phase 0 of Pacemaker action potential?

Upstoke- Opening of voltage gated Ca2+ channels

214

What happens to the fast voltage gated Na+ channels in Pacemaker action potential?

Are permanently inactivated

215

Why are fast voltage gated Na+ channels in Pacemaker action potential inactivated?

Because of less negative resting voltage of these cells

216

Which is the result inactivated fast voltage gated Na+ channels in Pacemaker action potential?

Results in a slow conduction velocity that is used by the AV node to prolong transmission from the atria to ventricles

217

What happens in phase 2 of pacemaker action potential?

Phase 2 is absent

218

Which channels are affected in phase 3 of pacemaker action potential? and How?

Inactivation of Ca2+ channels and ↑ activation of K+ channels → ↑ K+ efflux

219

How is phase 4 of pacemaker action potential known?

Slow diastolic depolarization

220

What happens during phase 4 of pacemaker action potential?

Membrane potential spontaneously depolarizes as Na+ conductance ↑

221

Which channels are different in pacemaker action potential and Ventricular action potential?

If different from INa in phase 0

222

Which phase acounts as the automaticity of SA and AV nodes?

Phase 4

223

In the pacemaker action potential what determines the Heart rate?

The slope of phase 4 in the SA node determines Heart Rate

224

What is the effect of ACh/ adenosine in heart?

↓ the rate of diastolic depolarization and ↓ Heart rate

225

What ↓ the rate of diastolic depolarization and ↓ Heart rate?

ACh/ adenosine

226

These is the effect of catecholamines in heart?

↑ depolarization and ↑ Heart Rate

227

Who ↑ depolarization and ↑ Heart Rate?

Catecholamines

228

What is the effect of Sympathetic stimulation in heart?

↑ the chance that If channels are open and thus ↑ Heart Rate

229

From how many mV does pacemaker action potential goes?

Little less -60 to little more than 0

230

In electrocardiogram what does P wave means?

Atrial depolarization

231

Who masks Atrial repolarization in Electrocardiogram?

By QRS comlex

232

What does PR interval means?

Conduction delay through AV node

233

How much time does PR interval normally last?

< 200 msec

234

What is QRS complex?

Ventricular depolarization

235

Time that QRS normally lasts?

< 120 msec

236

What happens in QT interval?

Mechanical contraction of the ventricles

237

What is the T wave?

Ventricular Repolarization

238

What electrocardiogram change indicates recent MI?

T wave inversion

239

What happens in ST segment?

Isoelectric, ventricles depolarized

240

When is U wave present in electrocardiogram?

Caused by hypokalemia, bradycardia

241

How is the speed of conduction?

Purkinje> atria> ventricles> AV node

242

How are classify the Pacemakers?

SA> AV> bundle of His/ Purkinje/ ventricles

243

How is the conduction Pathway?

SA node→ Atria → AV node → common bundle→ bundle branches → Purkinje fibers → ventricles

244

Which are the characteristics of SA node?

Pacemaker inherent dominance with slow phase of upstroke

245

Which is the delay of AV node?

100 msec

246

What does the Atrioventricular delay allows?

Allows time for ventricular filling

247

How is the potential measured in Electrocardigram?

In mV

248

From how many mV RS goes?

1.0 to -0.5

249

What are Torsades de Pointes?

Polymorphic ventricular tachycardia, characterized by shifting sinusoidal waveforms on ECG

250

Which is the possible progression of Torsades de Pointes?

To Ventricular fibrillation

251

What predisposes to Torsades de Pointes?

Long QT interval

252

Who causes Torsades de Pointes?

Drugs, ↓ K+, ↓ Mg2+, other abnormalities

253

What is included in the treatment of Torsades de Pontes?

Magnesium sulfate

254

Which medicines can cause Torsades de Pointes?

Some Risky Meds Can Prolong QT
Sotalol
Risperidone
Macrolides
Chloroquine
Protease inhibitors (navir)
Quinidine (class Ia, also class III)
Thiazides

255

Inherited disorder of myocardial repolarization

Congenital long QT syndrome

256

Which is the reason of Congenital long QT syndrome?

Typically due to ion channel defects

257

Which are the risks of Congenital long QT syndrome?

Increased risk of sudden cardiac death due to torsades de pointes

258

Which are Congenital long QT syndrome?

Romano Ward syndrome
Jervell and Lange Nielsen syndrome

259

Genetically which is the inheritance mode of Romano Ward syndrome?

Autosomal dominant

260

What is the phenotype affection in Romano Ward syndrome?

Pure cardiac phenotype (no deafness)
Congenital long QT syndrome

261

Inheritance mode for Jervell and Lange Nielsen syndrome

Autosomal recessive

262

Phenotype Characteristics of Jervell and Lange Nielsen syndrome

Sensorioneural deafness
Congenital long QT syndrome

263

Most common type of ventricular pre excitation syndrome

Wolff Parkinson White syndrome

264

What is Wolff Parkinson White syndrome?

Most common type of ventricular pre excitation syndrome

265

Which is the defect in Wolff Parkinson White syndrome?

Abnormal fast accessory conduction pathway from atria to ventricle bypasses tje rate slowing AV node

266

Which is the Abnormal fast accessory conduction pathway from atria to ventricle in Wolff Parkinson White syndrome?

Bundle of Kent

267

What are the results of Bundle of Kent in Wolff Parkinson White syndrome?

Ventricles begin to partially depolarize earlier, giving rise to characteristic delta wave with shortened PR interval on ECG

268

What is the Delta wave?

Partial Ventricles depolarization earlier

269

Which could be the complication of Wolff Parkinson White syndrome?

May result in reentry circuit → Supraventricular tachycardia

270

Which is the ECG pattern of Atrial Fibrilation?

Chaotic and erratic baseline(irregularly irregular) with no discrete P waves in between irregularly spaced QRS complexes

271

Which are the possible outcomes of Atrial fibrilation?

Can result in atrial stasis and lead to Thromboembolic stroke

272

Which are the treatments for Atrial Fibrilation?

Includes rate control, Anticoagulant, and possible pharmacological or electrical cardioversion

273

How is Atrial flutter seen in EKG?

A rapid succession of identical, back to back atrial depolarization waves

274

Which appearance do flutter waves have?

Sawtooth appearance

275

Which is the Pharmacological treatment for Atrial Flutter and what is its purpose?

Pharmacological conversion to sinus rhythm, Class IA, IC or III antiarrhythmics
Rate control

276

Which is the pharcmacological treatment for Atrial Flutter for Rate control?

β blocker or Calcium channel blockers

277

Definitive treatment for Atrial Flutter

Catheter ablation

278

On ECG what is seen in Ventricular Fibrilation?

A completely erratic rhythm with no identifiable waves

279

Which could be the prognosis of Ventricular Fibrilation?

Fatal arrythmia without immediate CPR and defibrillation

280

What happens in 1st degree AV block?

The PR interval is prolonged (> 200 msec)

281

How is the prognosis of 1st degree AV block?

Benign and asymptomatic

282

Which is the treatment for 1st degree AV block?

No treatment required

283

How are AV blocks Classified?

1st Degree
2nd Degree
Mobitz Type I
Mobitz Type II
3rd Degree

284

How else is Mobitz Type I known?

Wenckebach

285

What happens in Mobitz I?

Progressive lenghtening of the PR interval until a beat is dropped (a P wave not followed by QRS complex)

286

Explanation of Mobitz II

Dropped beats that are not preceded by a change un the length of the PR interval (as in type I).
It is often found as 2:1 block, where there are 2 or more P waves to 1 QRS response

287

Which is the prognosis of Mobitz II?

Might progress to 3rd degree block

288

How is Mobitz often treated?

With Pacemaker

289

AV block known as complete block

3rd degree

290

What happens in 3rd degree block?

The atria and the ventricles beat independiently of each other

291

Which is the ECG pattern of 3rd degree block?

Both P waves and QRS complexes are present, although the P waves bear no relation to the QRS complexes

292

Which rate is faster in 3rd degree block?

Atrial rate is faster than the ventricular rate

293

How is 3rd degree block ussually treated?

With pacemaker

294

Which infectious disease can result in 3rd Degree block?

Lyme disease

295

Who produces Atrial natriuretic peptide?

Released from atrial myocytes

296

When do atrial mycytes produce Atrial natriuretic peptide?

in response to ↑ blood volume and atrial pressure

297

Which is the effect of Atrial natriuretic peptide?

Vasodilation and ↓ Na+ reabsorption at the renal collecting tubule

298

Which is the renal effect of Atrial natriuretic peptide?

Constricts efferent renal arterioles and dilates afferent arterioles via cGMP, promoting diuresis and contributing to "aldosterone escape" mechanism

299

Another name for B type natriuretic peptide

Brain natriuretic peptide

300

Who releases B type natriuretic peptide?

Ventricular myocytes

301

When is B type natriuretic peptide release from ventricular myocytes?

In response to ↑ tension

302

How is B type natriuretic peptide compared to Atrial natriuretic peptide?

Similar physiologic action to ANP, with longer half life

303

What is the purpose to measured B type natriuretic peptide in blood test?

Diagnosing Heart failure (very good negative predictive value)

304

This is the recombinant form of B type natriuretic peptide

Nesiritide

305

When is Neseritide recommended?

For treatment of Heart failure

306

How does aortic arch transmits to solitary nucleus?

Via Vagus nerve

307

Where is Solitary nucleus located?

Medulla

308

Which stimulates are needed for Receptors in Aortic arch to respond?

Respond only to ↑ Blood pressure

309

Where is carotid sinus located?

Dilated region at carotid bifurcation

310

How does carotid sinus transmits to solitary nucleus?

Via Glossopharingeal nerve

311

Which stimulates are needed for Receptors in carotid sinus to respond?

Respond to ↓ and ↑ Blood pressure

312

Which is the importance of Barorreceptors?

Important in the response to severe hemorrhage

313

From Hypotension to Increased Blood Pressure how do Barorreceptors interact?

Hypotension- ↓ arterial pressure→ ↓ strecth → ↓ Afferent baroreceptor function → ↑ efferent sympathetic firing and ↓ efferent parasympathetic stimulation → Vasocontriction, → ↑ HR, ↑ contractility, ↑ BP

314

Which is the chain of events caused with Carotid massage?

↑ pressure on carotid sinus → ↑strethc → ↑afferent baroreceptor firing → ↑ AV node refractory period → ↓ HR

315

For what do Barorreceptors contribute?

To Cushing Reaction

316

What is the Cushing reaction?

Triad of hypertension, bradycardia and respiratory depression

317

How Baroreceptors contribute in Cushing reaction?

↑ Intracraneal pressure constricts arterioles → cerebral ischemia and reflexes sympathetic ↑ in perfussion pressure (hypertension) → ↑ stretch → Reflex baroreceptor induced-bradycardia

318

When is consider PO2 is decreased?

< 60 mmHg

319

Name the types of Chemoreceptors

Peripheral
Central

320

In peripheral chemoreceptors who are stimulated?

Carotid and aortic bodies

321

In peripheral chemoreceptors what stimulates Carotic and aortic bodies?

↓ PO2
↑ PCO2
↓ pH of blood

322

How do Central chemoreceptors work?

Are stimulated by changes in pH and PCO2 of brain interstitial fluid, which in turn are influenced by arterial CO2

323

Which Chemoreceptors do not directly respond to PO2?

Central

324

Organ with largest blood flow

Lung

325

Percentage of Cardiac output that flows through Lungs?

100%

326

Largest share of systemic cardiac output

Liver

327

Highest blood flow per gram of tissue

Kidney

328

Largest arteriovenous O2 difference

Heart

329

Why is heart conisder to have Largest arteriovenous O2 difference?

Because O2 extraction is 80%

330

In heart what increases O2 demand?

↑ Coronary blood flow, not by ↑ extraction of O2

331

What is PCWP?

Pulmonary Capillary wedge pressure

332

Which is the purpose to measuse Pulmonary Capillary wedge pressure?

Is a goof approximation of left atrial pressure

333

Which is the normal range for PCWP?

< 12 mmHg

334

In this pahology PCWP> LV diastolic pressure

Mitral stenosis

335

How is Pulmonary Capillary wedge pressure meassured?

Pulmonary artery catheter (Swan Ganz catheter)

336

Expected pressure of Right Atrial

<5 mmHg

337

Pressure of Right ventricle

25/5

338

In Right ventricle this is the normal pressure

130/10

339

Expected pressure in Aorta

130/90

340

What is the autoregulation?

How blood flow to an organ remains constant over a eide range of perfusion pressures

341

Main Organs that have autoregulation

Heart
Brain
Kidneys
Lungs
Skeletal muscle
Skin

342

Factors determining autoregulation in Heart

Local metabolites (vasodilatory):
CO2, adenosine, NO

343

Which factor determines autoregulation in Brain?

Local metabolities (vasodilatory)
CO2 (pH)

344

Factors determining autoregulation in Kidneys

Myogenic and tubuloglomerular feedback

345

Which factor determines autoregulation in Lungs?

Hypoxia causes Vasoconstriction

346

Which vasculature is unique in that hypoxia causes Vasoconstriction?

Pulmonary vasculature

347

Which pulmonary areas are perfused?

Only well ventilated areas are perfused

348

What is the effect of Hipoxia in the organs, other than the lungs?

Hypoxia causes dilation

349

Factors determining autoregulation in Skeletal muscle

Local metabolites:
Lactate, adenosine, K+, H+, CO2

350

Which is the factor determinining autoregulation in Skin?

Sympathetic stimulation most important mechanism- Temperature control

351

What do Starling forces determine?

Fluid movement through capillary membranes

352

Which are the factors in Starling forces?

Pc= Capillary pressure
Pi= Intersticial fluid pressure
πc= Plasma colloid osmotic pressure
πi= Interstisial fluid colloid osmotic pressure

353

What does Capillary pressure does?

Pushes fluid out of capillary

354

Effect og Interstitial pressure

Pushes fluid into capillary

355

What effect does plasma colloid osmotic pressure has on capillary?

Pulls fluids into capillary

356

Which effect does interstitial fluid colloid osmotic pressure has?

Pulls fluid out of capillary

357

How is Net filtration pressure calculated?

Pnet= (Pc-Pi)- (πc-πi)

358

In Starling forces what is Kf?

Filtration constant

359

Who determines the Filtration constant?

Capillary permeability

360

For capillary fluid exchange What is Jv?

Net fluid flow

361

How do you calculate Net fluid Flow?

Jv= (Kf)(Pnet)

362

What is edema?

Excess fluid outflow

363

Which are the common causes of Edema?

↑ capillary pressure
↓ plasma proteins
↑ capillary permeability
↑ interstitial fluid colloid osmotic pressure`

364

Example of ↑ capillary pressure

↑ Pc; heart failure

365

Which cases have ↑ capillary permeability?

↑ Kf; toxins. infections, burns

366

Name an example of ↑ interstitial fluid colloid osmotic pressure

↑ πi; Lymphatic blockage