Transitory Apical Hypokinesia in Hyperthyroidism

Cardiovascular symptoms are a frequent and, sometimes, predominant clinical manifestation in patients with hyperthyroidism. Reports of palpitations is present in most cases. Increased heart rate results both from increased sympathetic tone and reduced parasympathetic tone. It is common to observe frequency above 90 bpm at rest, dull diurnal variation and exaggerated elevation on exertion. A subgroup of patients may develop precordial pain similar to angina. In rare patients, generally young women, resting chest pain syndrome is associated with ischemic abnormalities on electrocardiogram. Cardiac catheterization demonstrates that most have angiographically normal coronary arteries. However, coronary vasospasms similar to those found in Prinzmetal angina are reported. Myocardial infarction rarely develops, and these patients seem to respond to calcium channel blockers or nitroglycerin.