Pulsus alternans is a cardiac abnormality whereby the regular alternating pulses have a perceptible difference in volume. This is a symptom of congestive heart failure. It can be induced by a number of mechanisms including atrial electrical stimulation, weak betas, aortic stenosis, occlusion of the inferior vena cava, and effusive pericarditis. However, it is considered a poor prognostic indicator and treatment should be directed towards correction of the underlying pathology.
The condition is usually accompanied by palpitations, fever, and chest discomfort. A decrease in systolic blood pressure may occur during inspiration. In addition, extracellular fluid may accumulate in the alveoli. These symptoms can also be associated with other conditions, such as pulmonary embolism or pleural effusion. Ultimately, patients with pulsus alternans may require aortic valve replacement.
Patients with pulsus alternans are at high risk for developing a stroke and heart attack. Therefore, they must be monitored closely. When the condition is detected, it is imperative that it is promptly evaluated by cardiology. Medications are available to reduce elevated blood pressure and treat underlying pathologies that may be causing the condition. Anticoagulants can also be prescribed to reduce the likelihood of a stroke.
To distinguish pulsus alternans from other heart disorders, a sphygmomanometer should be used to measure the systolic pressure of a patient. For pulsus alternans to be present, a palpable difference of at least 20 mmHg between large and small systolic beats is needed. As an alternative to the sphygmomanometer, plethysmographic waveforms can be used to assess a patient’s heart function. Although plethysmographic waveforms have not been proven to have a high sensitivity or specificity, they are useful in monitoring and evaluating patients with complex cardiac disease.
During a stress test, pulsus alternans is rarely found. However, it is important to remember that pulsus alternans does exist in patients with severe CHF. Moreover, it may occur in the right ventricle in the absence of left ventricular alternans. In these cases, a surveillance echocardiogram may be performed. Other methods of diagnosing pulsus alternans include examination of the arterial waveforms and palpation of the radial or femoral pulse.
Patients with pulsus alternans should be referred to an interventional cardiologist for further diagnostic evaluation. Treatment may involve aortic valve replacement, ischemic evaluation, or diuresis. If the condition is caused by aortic stenosis, anticoagulants can be administered to prevent a pulmonary embolism. Similarly, left ventricular alternans can be treated with diuretics for patients with left-sided heart failure. ACE inhibitors are also used to reduce elevated systolic blood pressure.
Pulsus alternans is associated with myocardial failure and hypertrophic cardiomyopathy. This condition is a risk factor for ventricular arrhythmia, stroke, and pulmonary embolism. However, it is not a life-threatening condition. Thus, it can be effectively diagnosed and treated.
The most common causes of pulsus alternans are aortic stenosis, constrictive pericarditis, and hypertrophic cardiomyopathy. Several studies have found a correlation between the presence of pulsus alternans and myocardial infarction. Some studies have also shown that aortic valve replacement and ischemic evaluation can successfully treat pulsus alternans in patients with aortic stenosis.
