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Cardiac decompensation is more prevalent in H patients with advancing age
(52). In older patients with underlying coronary artery disease, angina
pectoris can occur simultaneously with the onset of H, because of an increase
in myocardial oxygen demand, especially if tachycardia is present. Tachycardia
also reduces the time in diastole for coronary perfusion, decreasing myocardial
oxygen supply. H may also cause angina pectoris in patients with normal
coronary arteries. In elderly patients with apathetic H, AF or congestive
heart failure may be the only clinical manifestation of H. The high cardiac
output state, increased myocardial oxygen demand, decreased left ventricular
contractile reserve, reduced left ventricular filling because of the loss
of atrial contribution and the rapid ventricular rate all contribute to
the development of congestive heart failure in patients with H (5,50).
To determine the influence of age on the signs and symptoms of H, 880 patients were prospectively examined and compared with euthyroid controls (53). Many signs showed little change until after the fifth decade of life when they began to decrease gradually. Findings that increased with age were AF and weight loss. In a subgroup aged 60-83 yr, palpitations and tachycardia had a true- positive rate of 51% (sensitivity for H) and a false-positive rate of 9%. The prevalence of cardiovascular symptoms and signs in 85 patients >60 yr with H was also reported (54). Symptoms included dyspnea on exertion, orthopnea, or paroxysmal nocturnal dyspnea in 66%, palpitations in 42%, and angina pectoris in 20%. With respect to cardiac signs, a heart murmur was noted in 69%, a heart rate >100 beats/min in 58%, an AF in 45%, and a cardiomegaly in 11%. T-wave and ST-segment abnormalities (ECG) were present in 62 and 57%, respectively. Finally, In a recent study, the clinical profile of H was different in older people from that observed in younger patients (55). Comparison of classical signs of H between patients aged 70-90yr, mean 80yr and younger patients (23-50yr, 37yr) was done, and older patients were also compared with controls (81yr). Three signs were found in more than 50% of older patients: tachycardia, fatigue, and weight loss. Only AF (35 vs 2%) and anorexia (32 vs 4%) were found more frequently in older people. Comparison with older controls showed 2 signs that were highly associated with H in older people: tachycardia (Odd ratio: 11.2), and apathy (OR 15). |
