The following is a case report of a healthy 18-year-old woman who had bilateral Cervico- Thoracic sympathectomy done in two stages for severe hyperhidrosis in the palms of her hands.
Two episodes of asystolic arrest occurred during the 2nd stage left Cervico-Thoracic sympathec- tomy.
Thirty-five minutes after starting the operation, as the surgeon was retracting and dissecting the upper thoracic chain,
the cardiac monitor showed sudden onset of sinus bradycardia. The pulse rate was 50 beats per minute. Atropine 1·2 mg was given intravenously but cardiac asystole occurred.
External cardiac compression was started and another dose of atropine 1· 2 mg was given, followed by adrenaline 1·0 mg but there was no response. Following a second dose of adrenaline 1·0 mg and sodium bicarbonate 100 mEq, the
heart restarted with a marked sinus tachycardia.
The cause of hyperhidrosis apparently originates from some poorly understood stimulation of the sympathetic nervous system (Cloward 1969), and in sensitive patients this may possibly lead to excessive vagal stimulation to counteract it, as illustrated by the bradycardia and asystolic reaction to the sudden removal of the sympathetic control, and by the high doses of sympathomimetic drugs necessary to recommence cardiac activity. Anatomically the heart is innervated by the cardiac plexus which consists of the cardiac nerves derived from the cervical and upper thoracic ganglia of the sympathetic trunk and branches of the vagus.The pacemaker of the heart, the sino-atrial node, is innervated by both the parasympathetic and sympathetic nerves (King and Coakley 1958). The ventricular muscle of the heart is supplied solely by the sympathetic nerves, and the larger branches of the coronary arteries are also predominantly innervated by sympathetics (Woollard 1926). These factors may also have a bearing on the hazard of a bilateral cervico- thoracic sympathectomy, which leaves the heart solely under vagal control. Usually, following
denervation, the heart will initiate its own impulse, without recourse to external agencies, but there may be a place for transvenous electrode cardiac pacing, if spontaneous initiationof impulse is delayed, or bradycardia is severe.
R. F. Y. ZEE*
Royal Perth Hospital, Perth
Anaesthesia and Intensive Care, Vol. V, No. 1, February, 1977, Australia
