63 year old male with a long standing history of hypertension,
hyperlipidemia and long standing tobacco abuse presents
to the emergency room with a four hour complaint of severe
chest pain, nausea, dyspnea and diaphoresis.
On examination, the patient is in moderate distress. His
skin is warm and dry. BP is 95/60 mm Hg and pulse is regular
at 70/min. Neck veins are 4 cm above the clavicle at 30
degrees but there is no abdomino-jugular reflux There
is an S4 gallop at the apex together with a grade 2/6
systolic ejection murmur. Lungs are clear and the peripheral
pulses are normal. His ECG is shown, below.
The patient received sublingual NTG, 3 mg of intravenous
morphine sulfate, and ASA gr. V. Two minutes later, the
patient's BP drops to 70/30 mm Hg. Pulse is 60/min.
of the following represents the most likely cause
for his hypotension: