Physiological Adaptation Q 74
Which of the following is the most common symptom of myocardial infarction?
A. Chest pain
B. Dyspnea
C. Edema
D. Palpitations
Correct Answer: A. Chest pain
The most common symptom of an MI is chest pain, resulting from the deprivation of oxygen to the heart. The classic manifestation of ischemia is usually described as heavy chest pressure or squeezing, a “burning” feeling, or difficulty in breathing. The discomfort or pain often radiates to the left shoulder, neck, or arm. Chest pain may be atypical in a few cases. It builds in intensity over a period of a few minutes.
Option B: Dyspnea is the second most common symptom, related to an increase in the metabolic needs of the body during an MI. Despite variable prevalence estimates, dyspnea has been consistently associated with greater mortality in the general population. It is a more powerful predictor of clinical outcomes than objective physiologic measures such as pulmonary function testing in the general population, or angina in patients referred for cardiac evaluation.
Option C: Edema is a later sign of heart failure, often seen after an MI. All the factors which contribute to increased pressure in the left side and pooling of blood on the left side of the heart can cause cardiogenic pulmonary edema. The result of all these conditions will be increased pressure on the left side of the heart: increased pulmonary venous pressure–> increased capillary pressure in lungs–> pulmonary edema.
Option D: Palpitations may result from the reduced cardiac output, producing arrhythmias. In patients who describe the palpitations as a brief flip-flopping in the chest, the palpitations are thought to be caused by extrasystoles such as supraventricular or ventricular premature contractions. The flip-flop sensation is thought to result from the forceful contraction following the pause and the sensation that the heart is stopped results from the pause. The sensation of rapid fluttering in the chest is thought to result from a sustained ventricular or supraventricular arrhythmia.