Cardio - FA Anat/Phys 281- 289 Flashcards
(86 cards)
Enlargement of what part of the heart causes dysphagia or hoarseness - why?
LA - dysphagia (due to compression of the esophagus) or hoarseness (due to compression of the left recurrent laryngeal nerve, a branch of the vagus nerve).
Part of heart most commonly injured in trauma
RV
3 layers of pericardium
Fibrous pericardium Parietal layer of serous pericardium Visceral layer of serous pericardium
Pericardium innervated by?
phrenic n
Pericardititis causes referred pain to?
to the neck, arms, or one or both shoulders (often left).
Occlusion of which artery with lead to nodal dysfunction? Symptoms?
RCA - brady, heart block
Most common location of coronary a occlusion?
LAD
LAD supplies?
anterior of interventricular septum, anterolateral papillary muscle, and anterior surface of LV
PDA supplies?
AV node (dependent on dominance), posterior 1/3 of interventricular septum, posterior 2/3 walls of ventricles, and posteromedial papillary muscle
RCA supplies? Infarct may cause what sx?
SA node;
bradycardia, heart block
Peak flow in coronaries at what part of cardiac cycle?
early diastole
Stroke volume is affected by what 3 things?
1- afterload
2- preload
3- contractility
SV is inc by which parameters?
- inc Contractility
- dec Afterload
- inc Preload
What increases contractility?
- catecholamines ( stimulation via B1 receptor)
- Ca2+ channels phosphorylated—> Increasing Ca2+ entry—>leading to Increase Ca2+-induced Ca2+ release and increase Calcium storage in SR
- Phospholamban phosphorylation—>active Ca2+ ATPase—> Ca2+ storage in SRincrease intracellular Ca2++
- Inc IC Ca2+
- decrease EC Na+ ( via decrease Na/Ca2+ exchanger)
- digitalis ( blocks Na+/K+ pump)—> increaseing intracellular Na+—>decreasing Na+/Ca++ exchanger activity—> increase intracellular Ca++
What dec contractility and SV?
- Beta 1 blockade (decrease cAMP)
- HF w/ systolic dysfunction
- Acidosis
- hypoxia, hypercapnia, ( decrease Partial pressure of oxygen/increase partial pressure of CO2)
- non-dihydropyridine CCB
What parameter estimates preload?
ventricular EDV
( disclaimer ***depends on venous tone and circulating blood volume)
What drug decrease preload?
What drug decrease afterload?
What drugs decreases both?
- Preload - venous vasodilators/ venodilators (Nitroglycerin)
- Afterload - arterial vasodilators (Hydralazine)
- ACE, ARBS
How does LV compensate for inc afterload?
by thickening (hypertrophy) in order to dec wall tension.
What parameters will inc myocardial O2 demand?
- Inc contractility
- afterload,
- Heart Rate
- diameter of ventricle
Laplace’s law for wall tension
Wall tension = pressure x radius
wall stress = ?
wall stress = pressure x radius/2 x wall thickness
what are the 2 equations for stroke volume?
SV = CO/HR
SV = EDV - ESV
what is ejection fraction?
EF = SV/ EDV = EDV-ESV/EDV
Ejection Fraction is normal in diastolic or systolic Heart failure?
Ejection fraction is a measure/index of what?
EF is an index of ventricular contractility
EF decreased in systolic HF
EF is normal in diastolic HF



