Treatment and prevention of atrial fibrillation with non-antiarrhythmic pharmacologic therapy.

Atrial fibrillation is one of the most frequent heart rhythm disturbances found in clinical practice. Anticoagulation, rate control, cardioversion, and ablative procedures have been the mainstay of treatment. The frequent recurrence of atrial fibrillation and the side effects when antiarrhythmic drugs are used have led to dissatisfaction with available treatment of this arrhythmia. Pharmacologic therapy with angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, statins, and perhaps aldosterone and calcium channel blockers may have a role in the prevention of atrial fibrillation onset and recurrence. We summarize the possible biologic mechanisms and the clinical observations supporting the use of non-antiarrhythmic medications in the prevention of atrial fibrillation.

Reversible pulmonary hypertension, tricuspid regurgitation and right-sided heart failure associated with hyperthyroidism: case report and review of the literature.

Primary pulmonary hypertension carries a grim prognosis, therefore, it is imperative that prior to reaching this diagnosis, a thorough search be made for all possible causes of pulmonary hypertension. An uncommon cause of pulmonary hypertension amenable to treatment may occasionally be identified. This case report describes a young woman who presented with rapidly progressive right heart failure. Work up for the common secondary causes of pulmonary hypertension was negative, including, congenital intracardiac shunts, left-sided atrial or ventricular heart disease, left-sided valvular heart disease, disorders of the respiratory system including hypoxemia and pulmonary thromboembolic and venoocclusive disease, collagen vascular disease, portal hypertension, HIV infection as well as pulmonary hypertension secondary to drugs and toxins. The only concurrent illness identified was Graves disease. After treatment of hyperthyroidism there was complete resolution of the right heart failure, tricuspid regurgitation, and the pulmonary hypertension. Only a few cases of reversible pulmonary hypertension and right heart failure associated with hyperthyroidism have been reported worldwide. In these patients, the most striking feature has been the normalization of the cardiovascular findings after adequate treatment of hyperthyroidism. The exact reasons for the development of pulmonary hypertension in hyperthyroidism are unclear. Proposed mechanisms include high cardiac output-induced endothelial injury, increased metabolism of intrinsic pulmonary vasodilating substances resulting in elevated pulmonary vascular resistance, and autoimmune phenomenon. Hyperthyroidism should be included in the causes of secondary pulmonary hypertension and/or otherwise unexplained right heart failure. This is especially important because hyperthyroidism is a treatable entity and its cardiac manifestations may be completely reversible.