Victor Parsonnet

Deleterious effects of long-term single-chamber ventricular pacing in patients with sick sinus syndrome: The hidden benefits of dual-chamber pacing☆

Nine hundred fifty patients who received three modes of primary pacemaker systems (581 dual-chamber universal [DDD], 84 atrioventricular-sequential ventricular-inhibited [DVI] and 285 ventricular-inhibited [VVI]) over 12 years were studied retrospectively to determine the effect of pacing mode on patient longevity and the subsequent development of chronic atrial fibrillation or flutter. All patients were followed up continuously for 7 to 8 years. Patients were classified according to indication for permanent pacing (sick sinus syndrome or other indication), age at pacemaker implantation (less than or equal to 70 or greater than 70 years) and history of atrial tachyarrhythmia. Fourteen percent of patients developed atrial fibrillation at some time during the study period. Of those, 4% had a DDD pacemaker, 8% had a DVI pacemaker and 19% had a VVI pacemaker. At 7 years, atrial fibrillation was significantly more frequent in the VVI group than in the DDD and DVI groups. In patients with sick sinus syndrome, the incidence rate was even higher in the VVI group but approximately the same in the DDD and DVI groups. Patients in the VVI and DVI groups who had had previous atrial tachyarrhythmia had a significantly higher incidence of atrial fibrillation at 7 years than did those in the DDD group. During the entire period there were 130 deaths in the study group, including 22% of patients with a DDD pacemaker, 38% of those with a DVI pacemaker and 50% of those with a VVI pacemaker. Patient survival at 7 years was lower in the VVI group than in the DDD or DVI groups.(ABSTRACT TRUNCATED AT 250 WORDS)

A four-year experience with preoperative noninvasive carotid evaluation of two thousand twenty-six patients undergoing cardiac surgery

From January 1979 through December 1982, 2026 patients scheduled to undergo open heart surgery were evaluated by a preoperative battery of noninvasive carotid tests including phonoangiography, oculopneumoplethysmography, pulse-timing oculoplethysmography, periorbital Doppler examination, and during the last 12 months, continuous-wave Doppler ultrasonography with spectral analysis. The incidence of hemispheric neurologic deficit following cardiac surgery in the 47 patients with carotid disease was 14.9%; the incidence in patients with no carotid disease was 1.9% (p less than 0.001). Fourteen of the 47 patients were not candidates for carotid surgery because of unilateral occlusion in 13 and bilateral occlusion in one. Three of the 14 (21.4%) had intraoperative strokes on the appropriate side. Thirty-three of the 47 had operable carotid disease. Four with unilateral stenosis had no carotid surgery; one had a postoperative deficit on the side referable to the nonstenotic artery. Eighteen with unilateral stenosis underwent simultaneous cardiac and carotid surgery; one (5.6%) had a transient deficit. Seven patients with bilateral stenosis underwent cardiac and unilateral carotid surgery; no deficits occurred. Four patients with unilateral stenosis and contralateral occlusion underwent combined surgery; one had a transient ischemic attack and one a fatal stroke, both referable to the hemisphere ipsilateral to the occlusion. It appears that the presence of carotid disease increased the risk of stroke during heart surgery. Proof that carotid endarterectomy lowers this risk awaits a prospective randomized trial.

Long-Term Efficacy of Subendocardial Resection in Refractory Ventricular Tachycardia: Relationship to Site of Arrhythmia Origin

Subendocardial resection is performed in patients with ventricular tachycardia (VT), but its efficacy as related to the site of origin of VT is problematic. We analyzed the efficacy of subendocardial resection in 24 patients with coronary artery disease and VT. All patients underwent preoperative and intraoperative mapping before subendocardial resection. Postoperative electrophysiologic studies were performed in the drug-free state 7 to 14 days after subendocardial resection. Group 1 (n = 14) had anterior, septal, or lateral sites of origin, and Group 2 (n = 10) had inferior or posterior sites of origin. Localization of presystolic electrical activity during VT by preoperative and intraoperative mapping was comparable in both groups (100%). Resectability of the site of origin was higher in Group 1. Induction of VT during a postoperative electrophysiological study was higher in Group 2. Perioperative mortality was comparable. Postoperative antiarrhythmic therapy was instituted more frequently in Group 2. Actuarial survival analysis showed improved patient survival at one year after subendocardial resection for both groups. The efficacy of subendocardial resection is related to site of origin of VT: Subendocardial resection is less efficacious in VT with inferior or posterior sites of origin because of nonresectability of the arrhythmogenic area.

Femorofemoral grafts for lower limb ischemia caused by intra-aortic balloon pump

From January 1975 to December 1985, 1454 patients had an intra-aortic balloon inserted for cardiac assistance. Eighty balloon-dependent patients had severe limb ischemia and required a femorofemoral graft (FFG) (5% of the total group of patients). Twenty-nine of the 80 patients with grafts (or 36%) left the hospital and 28 were followed up for an average of 40 months to determine late complications associated with the crossover grafts. All grafts remained patent. The 28 patients were classified into five groups according to the degree and type of lower limb ischemia. Group I consisted of 13 asymptomatic patients (46%); group II had four (14%) patients with mild claudication caused by preexisting peripheral arteriosclerosis; group III comprised four patients (14%) without preexisting disease but claudication subsequent to the FFG; group IV had five patients with irreversible ischemic sequelae before grafting ending in amputation, foot drop, or persistent paresthesia; and group V consisted of two patients with graft infection (7%). The perioperative mortality rate of the balloon-dependent patients with an FFG (64%) reflects the gravity of the cardiac condition. Placement of an FFG to relieve limb ischemia in these patients is followed by few immediate or late complications in the survivors and any persistent limb changes were related to the prolonged ischemia present before revascularization. Our data suggest that in balloon-dependent patients with limb-threatening ischemia, aggressive use of the FFG is limb-saving, durable, and allows continuation of balloon support.

Transvenous Placement of a Pacemaker Lead Through an Introducer Despite Long‐standing Subclavian‐Vein Occlusion

Under ordinary circumstances complete chronic subclavian vein occlusion precludes using that vein for the pacemaker lead. There are circumstances, however, in which a patent vein beyond the obstruction can be reached with an introducer needle, thus permitting transvenous access similar to any other introducer‐assisted implantation. A case exemplifying this point is described. Patency of the right subclavian vein beyond an occlusion was demonstrated by angiography, and a new dual‐chamber pacemaker lead was inserted through that site by use of the introducer method.

Pulmonary Inactivation of Vasopressors Following Cardiac Operations

Vasoactive drugs were infused through catheters in the right atrium and then the left atrium of 34 patients who required either vasopressor or vasodilator support following cardiac operation to determine if the route of infusion affected the aortic blood concentration of these agents. Drugs were given through the right atrium for one hour and then the left atrium for an hour. Both central aortic and pulmonary arterial blood were assayed for drug concentrations, and hemodynamic measurements were made. Sixteen patients receiving dopamine hydrochloride through the left atrium had a 36 +/- 12% (+/- standard error of the mean) increase in aortic concentration of the drug (p less than 0.005) and a 37 +/- 14% increase in cardiac index (p less than 0.005) compared with administration through the right atrium. Seven patients receiving epinephrine showed a 59 +/- 21% increase in aortic concentration (p less than 0.05) and a 21 +/- 10% increase in cardiac index (p greater than 0.05, not significant). Eleven patients receiving sodium nitroprusside achieved a 99 +/- 25% increase in aortic concentration (p less than 0.005) and a 20 +/- 7% increase in cardiac index (p less than 0.05). In all instances, significantly higher central aortic blood concentrations were achieved during left atrial (LA) versus right atrial (RA) infusions. Changes in blood concentration of the drug between the pulmonary artery and the aorta during RA infusion suggest removal or inactivation of these drugs in the pulmonary vasculature.(ABSTRACT TRUNCATED AT 250 WORDS)