[Severe cardiac failure in Kearns-Sayre syndrome]. / Insuficiencia cardíaca grave en el síndrome de Kearns-Sayre.

Mitochondrial disorders are a group of diseases that can affect virtually all organ systems. A 19 year old man was seen in 1993 with neurologic abnormalities consisting of impaired function of muscles, diplopia, progressive loss of vision, impaired phonation and swallowing, during the last 10 years. Physical examination disclosed moderate wasting of the four limb muscles, mild motor weakness of neck muscles, symmetrical hyporeflexia, cerebellar dysfunction, severe external ophtalmoplegia and ptosis. Fundii oculi examination showed retinitis pigmentosa. The electromyogram demonstrated myopathic changes with normal nerve conduction velocities. The cerebrospinal fluid was normal, except for a mild increase in lactic acid. Histochemical study of a muscle biopsy specimen demonstrated ragged red fibers and increase of the subsarcolemal oxidative activity of mitochondriae. The diagnosis of Kearns-Sayre disease was confirmed and he was discharged advising physical therapy. On February 1995, he was again admitted, this time with right cardiac failure and worsening of all his previous symptoms and signs. He complained of myalgias and his muscle weakness was more striking on clinical examination. Echocardiography showed biventricular dilatation and left ventricular hypertrophy with preserved systolic function. A new muscle biopsy revealed an heteroplasmic deletion of 5 Kb with 80% of mutant mitochondrial DNA. In brief, we report a patient with the clinical phenotype of Kearns-Sayre syndrome who presented an acute congestive cardiac failure due to cardiomyopathy, an association which has seldom been, reported in the literature.

Ventricular fibrillation after intravenous atropine in a patient with atrioventricular block.

A 69-year-old black woman with complete AV block developed ventricular fibrillation following an IV injection of 1 mg of atropine sulphate. After a successful DC countershock, the ECG showed a polymorphous ventricular tachycardia which subsided spontaneously. Cardiac catheterization revealed a small left ventricular diverticulum and normal coronary arteries. This seems to be the first reported case of atropine-induced ventricular fibrillation in a patient with complete AV block. The fact that this occurred without previous change of the ventricular rate suggests that the adverse action of atropine was mediated through a mere vagolytic effect at the ventricular level.