High Yield points regarding USMLE and pLAB
#Heart_Sounds_and_Murmurs
A S4 heart sound CANNOT be present during atrial fibrillation (atrial kick is required).
A S3 heart sound CANNOT be present in the setting of severe mitral stenosis.
A S3 heart sound can be present in athletes, pregnant females and other young healthy individuals.
A S3 heart sound can indicate severe systolic heart failure.
A S4 heart sound is always pathologic and can indicate diastolic heart failure, left ventricular hypertrophy or active myocardial ischemia.
Factors that increase the intensity of the S1 heart sound include short PR interval, fast heart rate and mild mitral stenosis.
Factors that decrease the intensity of the S1 heart sound include long PR interval, slow heart rate and severe mitral stenosis.
A fixed split S2 heart sound can be from an atrial septal defect.
A paradoxically split S2 heart sound can be caused by aortic stenosis, hypertrophic obstructive cardiomyopathy or a left bundle branch block.
A widened split S2 heart sound can be caused by severe mitral regurgitation, pulmonic stenosis or a right bundle branch block.
Large systolic jugular venous pulsations can be from V waves due to severe tricuspid regurgitation.
A holosystolic murmur at the left lower sternal border louder with inspiration is due to tricuspid regurgitation (Carvallo’s sign).
The aortic stenosis murmur can radiate to the cardiac apex where it sounds holosystolic and can mimic the murmur of mitral regurgitation (Galiveriden phenomenon).
The three physical exam findings that correlate with severity of aortic stenosis include the timing of the murmur peak in systole (late peak is severe), the intensity of the S2 heart sound (soft or absent is severe) and “pulsus parvus et tardus”.
The late diastolic crescendo portion of a mitral stenosis murmur disappears when atrial fibrillation is present due to the loss of the atrial kick.
The murmur of aortic regurgitation is located at the right upper sternal border (aortic post) ONLY if the etiology is aortic root dilation. If valve leaflet pathology is the cause then the murmur is heard at the left lower sternal border.
The best position to hear the murmur of aortic regurgitation is to have the patient lean forward and listen after a forced, held expiration.
As aortic regurgitation worsens, the murmur becomes shorter in early diastole due to the aortic and left ventricular pressure equalizing more quickly.
The two murmurs that can be heard in the patient’s back are mitral regurgitation and coarctation of the aorta.
The Austin-Flint murmur is a diastolic rumble at the cardiac apex in a patient with aortic regurgitation and occurs from the regurgitant jet striking the anterior mitral leaflet.
There are multiple peripheral physical exam findings in patients with severe aortic regurgitation due to the high stroke volume (see Aortic Regurgitation Review)
When the mitral regurgitant jet is eccentrically directed posterior (anterior leaflet involvement), the murmur radiates to the back. When directed anterior (posterior leaflet involvement), the murmur radiates to the cardiac base.
The murmur of mitral regurgitation increases with handgrip and transient arterial occlusion since these maneuvers increase afterload.
The earlier the opening snap in a patient with mitral stenosis, the more severe it is due to higher left atrial pressures forcing the valve open immediately in early diastole.
The murmur of a small ventricular septal defect (VSD) is very loud a frequently associated with a thrill. This murmur is referred to as “maladie de Roger”
The murmur of an atrial septal defect is a systolic, crescendo-decrescendo murmur at the pulmonic listening post due to increased pulmonic valve flow. There is frequently a fixed splitting of the S2 heart sound.
The murmur of a patent ductus arteriosus is continuous throughout systole and diastole since the aortic pressure (normally 120/80) is ALWAYS higher than the pulmonary artery pressure (normally 25/10) in both systole and diastole.
A right ventricular heave can be present from severe pulmonary hypertension.
Cannon A waves can be seen in the jugular venous pulsations when the atrium contracts at the same time as the ventricle (against a closed tricuspid valve) which occurs in the setting of AV dissociation (complete heart block or ventricular tachycardia).
Roth spots, Janeway lesions and splinter hemorrhages are all peripheral signs of endocarditis.
Immediate therapy of patients(non IV drug abusers) having Endocarditis is Gentamysin and Vencomysin
Either production of new murmurs but any change in the existing murmur is also a cause of Endocarditis
Unequal radial pulses can be a sign of aortic dissection (with subclavian artery compression) OR from atherosclerotic subclavian arm occlusion.
Always check blood pressure in both arms in acute chest pain patients to help diagnose aortic dissection (will be markedly lower in one arm, usually the left, if the subclavian artery is involved
#USSM