Cardiac myxomas originating from the left ventricular free wall are extremely rare. A 32-year-old Swiss male was found to have a 5 x 3 x 3 cm myxoma originating from the left ventricular free wall using transthoracic echocardiography. The tumour was successfully treated by surgical excision but the mitral valve could not be preserved because of an untypical interference of the myxoma with the subvalvular apparatus.

Behavioral arousal may trigger malignant cardiac arrhythmias. To study the effect of arousal on ventricular tachycardia, pigs were instrumented with catheters to measure mean arterial pressure and sample plasma catecholamines and left anterior descending coronary artery snares for occlusion 1 wk later. Bipolar pacing catheters were placed in the right ventricular apex to induce ventricular tachycardia. One week after occlusion, electrophysiological testing was repeated before and immediately after arousal caused either by restraining and lifting the pig in a canvas sling or by bringing a stall mate into the room. The number of stimuli needed to induce monomorphic ventricular tachycardia was reduced by both types of arousal (P less than 0.05) compared with control conditions. Ventricular tachycardia rate was increased 60 +/- 17 beats/min after lifting stimulation (P less than 0.05). When beta 1-receptor blockade was induced by metoprolol, inducibility of ventricular tachycardia and rate were not different from control. Thus, in pigs, arousal may facilitate arrhythmogenesis. This effect may be mediated by sympathetic neural activity in the heart because it was annulled by beta 1-adrenergic blockade.

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