Heart sounds and intracardiac pressures Heart sounds S

Heart sounds and intra-cardiac pressures.

Heart sounds: • S 1: Due to closure of mitral and tricuspid valves. • Softer: Cardiac failure, pericardial effusion, valvular incompetence • Louder: Tachycardia, shortened PRinterval, mitral stenosis with still pliable valve

• S 2: Closure of aortic and pulmonary valves. • Louder: Systemic and/or pulmonary HT • Softer: Pericardial effusion, hypotension, valvular incompetence

Splitting of S 1 and S 2: • Normally: Deep inspiration, RV-filling, split S 1: Tricuspid valve closes after mitral valve. Physiologicl splitting of S 1. • ASD: Fixed splitting of S 1 • Electrical disturbances: RBBB, LBBB

Splitting of S 2: • Any condition(s) impairing emptying of LV or RV. • Valvular stenosis, pulmonary HT etc

S 3: • Caused by rapid ventricular filling • Can be normal in the young • Pathology: • Valvular incompetence

S 4: • Caused by stiff ventricle • During atrial contraction • AF: S 4 ? or not

Intra-cardiac pressures: • Intra-atrial pressure: RA: a, c, v waves on flebogram: From negative to +8 mm. Hg • LA: Also a, c, v waves: Maximum +12 mm. Hg: Measured by catheter: Swan-Ganz • Pulmonary capillary wedge pressure:

Clinical application of wedge pressure: • Pulmonary edema: Cardiac vs non-cardiac • Increased wedge pressure=cardiac origin: • LV-failure or mitral valve: stenosis or acute incompetence • LV-failure: Systolic vs diastolic

Intra-ventricular pressures: • RV: From 0 to 25 mm. Hg • LV: From 0 to 125 mm. Hg

• LV pressure-volume curve • Diagram on cardiac cycle • La Place`s law • Poiseulle`s law • Study from textbook: Ganong