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A 54-year-old man with a history of type 2 diabetes mellitus comes to the emergency department due to shortness of breath. Blood pressure is 146/92 mm Hg, and respirations are 26/min. Oxygen saturation is 87% on room air. Auscultation findings over the cardiac apex are given below. Based on the auscultation findings, which of the following is the best initial therapy for this patient?
Show Explanatory Sources
Extra (gallop) heart sounds | ||
Features | Associated pathology* | |
S3 |
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S4 |
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*S3 can be normal in children, young adults & during pregnancy. S4 can be normal in the elderly (eg, age >70). EF = ejection fraction; LV = left ventricular. | ||
In addition to the normal S1 and S2 on cardiac auscultation, this patient has a low-pitch extra heart sound occurring just after S2, known as an S3. The presence of an S3 produces a rhythm that may sound like "ken-tuc-KY," with the S3 corresponding to the third syllable.
An S3 is believed to represent reverberant sound that is created when blood fills an enlarged ventricular cavity during passive diastolic filling. Although an S3 can be normal in children and young patients (especially well-trained athletes), it typically indicates pathologic ventricular cavity enlargement (eg, heart failure with reduced ejection fraction) in older patients (eg, age >40). In addition to an S3, this patient has several other signs and symptoms consistent with decompensated heart failure, including shortness of breath, tachypnea, and hypoxemia; therefore, intravenous diuretics are most appropriate.
In contrast to an S3, an S4 occurs in late diastole and is indicative of a stiff left ventricular wall, as occurs with concentric hypertrophy due to chronic hypertension. Both an S3 and S4 are best heard at the cardiac apex with the bell of the stethoscope.
(Choice A) Inhaled bronchodilators are appropriate for treatment of an acute exacerbation of asthma or chronic obstructive pulmonary disease. However, such patients typically have wheezing on chest auscultation.
(Choice B) Beta blockers are helpful in management of chronic heart failure with reduced ejection fraction, but their role in management of acute decompensated heart failure (ADHF) is minimal. They are contraindicated in patients with severe ADHF as they lengthen diastolic filling time (and slightly decrease contractility) and may worsen pulmonary edema.
(Choice C) Diltiazem is contraindicated in patients with ADHF as the negative inotropic effect (ie, reduced contractility) can worsen symptoms.
(Choice E) Pericardiocentesis may be indicated in management of a pericardial effusion. Pericardial effusion commonly occurs as a complication of acute pericarditis, which may be recognized by a triphasic pericardial friction rub best heard at the left lower sternal border with the patient leaning forward.
Educational objective:
An S3 is a low-pitch extra heart sound heard in early diastole, just after S2. It is thought to represent reverberant sound created by blood filling an enlarged ventricle during passive diastolic filling, and it is commonly indicative of decompensated heart failure with reduced ejection fraction.