Two hours after thrombolytic therapy was completed, our patient had an hypotensive episode. He had no chest pain, but his skin was cool and clammy. His heart rate was sixty, his rhythm was normal sinus and his blood pressure was 75/45 mmHg.
Hypotensive episode
His physical examination further revealed a decrease in amplitude of his carotid arterial pulse. His central venous pressure had fallen, as his jugular venous pulse is no longer visible. He had no third heart sounds or murmurs and his lungs were clear. Hi ECG was unchanged. An echocardiogram was performed at the bedside and showed marked hypokinesis of the inferoposterior wall with normal right ventricular size and function.
Likeliest diagnosis
His physician felt that the likeliest diagnosis was hypovolemia. He had a history of diaphoresis and vomiting and his examination revealed a low central venous pressure. No likelier cause was suggested by his bedside evaluation. In addition, inferoposterior wall ischemia may initiate a reflex that results in bradycardia and peripheral vasodilatation with a shift in intravascular volume.
Treated promptly
Hypotension is a serious complication of myocardial infarction and was treated promptly. He was given a fluid bolus and his blood pressure rose to 110/70 mmHg and he became warm and dry. When it is uncertain that the fluid treatment is appropriate, infrequently the placement of a Swan-Ganz flotation catheter in the pulmonary artery may be necessary to monitor the pulmonary capillary wedge pressure and cardiac output.
Other etiologies
Other common etiologies of hypotension that are readily reversible are medication side effects and arrhythmias.
Additional causes of hypotension
Additional causes of hypotension in this clinical setting include pump failure from a large area of infarction and/or ischemia, mechanical causes such as ventricular or papillary muscle rupture and tamponade associate with pericardial effusion, right ventricular infarction and blood loss associated with thrombolytic therapy. These diagnoses were felt to be less likely than hypovolemia, based on a careful cardiovascular examination and supported by the immediate electrocardiogram and echocardiogram.