CardioAnesthesia

Question 1

Miocardial perfusion

Answer 1

Dominance : coronary supply to POSTERIOR DESCENDING ARTERY

RIGHT 65% left 15% ( circumflex)

Anterior wall: Left anterior descending artery
Lateral wall: left circumflex artery
Posterior wall: RCA

*posteromedial papillary muscle rupture > anterolateral because of double blood supply

Question 2

Coronary perfusion pressure

Answer 2

CPP= aortic dyastolic pressure- LVEDP

Question 3

Intra aortic ballon pump

Answer 3

Fill with hellium laminar flow pass through

Indication: cardiogenic shock
Failure to wean from CPB
SEVERE MITRAL REGURGITATION
bridge to transplantation
Right ventricular disfunction

Contraindications: aortic insufficiency
Aortic dissection
Arterial injury
Ischemia - plaque
Thromboembolism
Hemolysis
Infection

The ballon is inflated to augment aortic diastolic pressure CPP

In early diastole to late diastole

Question 4

CPB goals

Answer 4

Pump blood flow 1-3 ml/min/m2

MAP 50-90 mmhg
SatvO2 65%

Question 5

Fick method to measure CO

Answer 5

Oxygen consumption is equal to CO+ difference in oxygen content A-V

CO = Vo2 /(CaO2-CvO2)

A-V difference:1.34 mlO2/g Hb x[hb] X( diferencia saturacion A-V)

Limitaciones : 
Pneumonia
High output states 
Shunt 
Narrow differences A-V

Question 6

Brugada

Answer 6

Channelopathy Na

EKG PSEUDO RIGHT BBB

Wide QRSwith R’ V1 exaggerated S wave in V5V6
ST elevations in V1-V3

Cardiodesfibrilador

Anesthesia : not propofol infusion or bupivacaine

No BB
Avoid sodium channel blocker’s

Question 7

Benzold jarish

Answer 7

Response to noxious stimulus to ventricule

Aferent : vagus 
Increased parasympathetic response 
Response bradycardia 
                   Hypotension 
                  Coronary vasodilation

Question 8

Brainbridge

Answer 8

Stretch Receptor between atria an vena cava
Afferent through vagus nerve to CV center in medulla

Increased in stretch (pressure) cause inhibition of PNS= increased in heart rate

Decreased in stretch : decreased in HR ( neuroaxial)

Question 9

La place law

Answer 9

Wall stress = pressure x radius/2x wall tickness

Question 10

Sistemic vascular resistance

Answer 10

SVR= CVP-MAP/CO x80 dynes/sec/cm5

Normal 700-1500 dynes/sec/cm5

Question 11

Normal oxigen delivery

Answer 11

Normal 900-1000 ml/min

Critical ( not supply demand( <700 ml/min

Question 12

Stroke volume/ ejection fraction

Answer 12

SV= EDV-ESV
EF= SV /EDV x 100 =%

Question 13

HOCM

Answer 13

The goals of anesthetic management of HOCM include: (1) reduced myocardial contractility, (2) maintenance of (or increase in) of SVR, and (3) increased preload and cardiac output. Etomidate is a good choice for intravenous induction in patients with HOCM given its ability to maintain or increase SVR

Question 14

Stents and surgery

Answer 14

The minimum time after placement of a drug-eluting stent is six months for elective procedures.

everolimus in newer stents and paclitaxel in older stents.

If the patient had received a bare-metal stent, a 30-day interval could be considered.

Question 15

early invasive strategy:

Answer 15

ACC/AHA guidelines, qualify for early invasive strategy:

• Recurrent angina or ischemia at rest with low-level activities despite intensive medical therapy
• Elevated cardiac biomarkers
• New ST-segment depression
• Signs or symptoms of heart failure or new or worsening mitral regurgitation
• Hemodynamic instability
• Sustained ventricular tachycardia
• PCI within 6 months
• Prior coronary artery bypass
• High-risk TIMI score (> 2 points)
• Reduced left ventricular function (LVEF < 40%)

Question 16

TAVR

Answer 16

AVRs are currently only indicated for symptomatic aortic stenosis.

TAVR is most beneficial for patients who are considered high surgical risk, and conversely, low-risk patients with severe AS should be considered for surgical repair.

In patients who are extremely high risk such as those whose survival is expected to be less than 12 months, TAVR may provide a small benefit over standard medical therapy.

Question 17

Torsades de pointes

Answer 17

Tto

includes recognizing TDP from normal VT and removal or correction of the offending agent. Correcting electrolytes with the early use of magnesium is recommended. Magnesium can be given as an initial 1-2 gram IV bolus over 30-60 seconds, which can then be repeated in 5-15 minutes. Alternatively, a continuous infusion can be started at a rate of 3-10 mg/min. Magnesium is effective even in patients with normal magnesium levels.

Torsades can be induced by many antiarrhythmic drugs including class Ia (sodium channel blockade) and class III (inhibit potassium channels) by prolonging the QT interval.

Hypokalemia and hypomagnesemia are also known to be associated with TDP

Question 18

Mitral regurgitation

Answer 18

Mitral regurgitation patients should be kept “fast, full, forward” by avoiding bradycardia, ensuring adequate preload, and avoiding high afterload

There are several goals for anesthetic management of patients with severe mitral regurgitation.

1) Bradycardia should be avoided as this increases the regurgitant volumes accumulating during systole. In addition, a slower heart rate increases ventricular diastolic filling time which will increase the regurgitant volume during the next systole.
2) Normovolemia should be maintained in order to avoid left ventricular and mitral annular distension and the subsequent increase in regurgitant volume. Hypovolemia is not helpful either.
3) Afterload, measured in terms of systemic vascular resistance (SVR), should be kept relatively low to help with aortic flow of the generated cardiac output. This can be accomplished via vasodilators, inodilators, and/or an intra-aortic balloon pump.
4) Avoid pulmonary vasoconstriction. Patients with severe MR have varying degrees of pulmonary hypertension. Factors that cause pulmonary vasoconstriction (e.g. acidosis, hypoxia, and hypercapnia) should therefore be avoided.

Question 19

Hypertrophied cardiomyopathy

Answer 19

Factors that promote LVOT obstruction in HCM include: tachycardia, hypovolemia, vasodilation, and a high chronotopic/inotropic state. In this scenario, options for the treatment of hypotension are phenylephrine, fluid boluses, and beta-blockade.

the anesthetic goals are:
Maintenance of sinus rhythm
Reduction in sympathetic stimulation
Maintenance of left ventricular filling
Maintenance of systemic vascular resistance

Septal myectomy is the treatment of choice in a patient with hypertrophic cardio