A 53-year-old man comes to the office due to difficulty breathing and increasing fatigue. He has shortness of breath at night and has been sleeping in a recliner to help relieve his dyspnea. Medical history is significant for hypertension and hyperlipidemia. Two months ago, the patient suffered a myocardial infarction that was not revascularized due to a delay in seeking treatment. He quit smoking afterward, but had previously smoked a pack of cigarettes daily for 25 years. On cardiac auscultation, a low-frequency diastolic heart sound is heard shortly after the second heart sound when the patient lies in the left lateral decubitus position. Cardiac imaging shows hypokinesis of the left ventricular free wall. Which of the following is most likely to accentuate this patient's abnormal auscultation finding?

Question

A 53-year-old man comes to the office due to difficulty breathing and increasing fatigue.  He has shortness of breath at night and has been sleeping in a recliner to help relieve his dyspnea.  Medical history is significant for hypertension and hyperlipidemia.  Two months ago, the patient suffered a myocardial infarction that was not revascularized due to a delay in seeking treatment.  He quit smoking afterward, but had previously smoked a pack of cigarettes daily for 25 years.  On cardiac auscultation, a low-frequency diastolic heart sound is heard shortly after the second heart sound when the patient lies in the left lateral decubitus position.  Cardiac imaging shows hypokinesis of the left ventricular free wall.  Which of the following is most likely to accentuate this patient's abnormal auscultation finding?

Quizplus · Accepted Answer

11ec160b_3c94_f8fc_9249_17c25e6d05f5_MD0001_00 This patient has decompensated heart failure (fatigue, dyspnea) with an audible S3, a low-frequency sound that occurs during early diastole, just after S2. An S3 is likely caused by reverberation of sound within the ventricular cavity during rapid passive ventricular filling. S3 can be a normal finding in healthy children and young adults; however, in patients age >40 it is considered abnormal and suggests ventricular volume overload or enlargement. It is often heard with aortic or mitral regurgitation or heart failure with reduced ejection fraction (eg, dilated cardiomyopathy, ischemic heart disease). In this patient's case, imaging is consistent with left ventricular systolic dysfunction secondary to the patient's recent myocardial infarction. An S3, and the other commonly heard left ventricular gallop, S4 (caused by blood striking a stiff ventricular wall during atrial contraction at the end of diastole), are best heard with the bell of the stethoscope over the cardiac apex while the patient is in the left lateral decubitus position. Listening at end expiration makes the sound even more audible by decreasing lung volume and bringing the heart closer to the chest wall. (Choices A, B, C, and E) Medications and maneuvers that decrease venous return to the heart reduce ventricular blood volume and are likely to lessen the intensity of an S3. Amyl nitrate inhalation causes dilation of venous capacitance veins to decrease venous return, furosemide injection causes brisk diuresis to reduce intravascular blood volume, standing causes blood to pool in the legs to reduce venous return, and Valsalva strain phase increases intrathoracic pressure to compress the vena cava and reduce venous return. Educational objective: An S3 is a low-frequency sound occurring during early diastole, just after S2. Left ventricular gallops (S3 and S4) are best heard with the bell of the stethoscope over the cardiac apex while the patient is in the left lateral decubitus position at end expiration.

A 53-Year-Old Man Comes to the Office Due to Difficulty