Cardiac rhythm disturbances early after orthotopic heart transplantation: Prevalence and clinical importance of the observed abnormalities

Abstract

To precisely define the incidence, type and consequences of cardiac arrhythmias early after heart transplantation, 25 cardiac transplant recipients were monitored continuously for 728 days from the day of surgery to discharge or death. A subset of 15 patients had sinus node function studies with overdrive suppression performed weekly at the time of endomyocardial biopsy. Results revealed sinus bradycardia in 10 patients (40%) and junctional bradycardia in 6 (24%). Supraventricular tachycardia in the form of atrial tachycardia, atrial fibrillation and atrial flutter occurred in 11 patients (44%). Ventricular tachycardia occurred in 15 patients (60%) and was nonsustained in all. Cardiac pacing for 1,403 h was used in nine patients with a pulse rate less than 50 beats/min; seven recovered and permanent pacing was instituted in two. In the subgroup that had sinus node function studies, seven patients were identified with clinical bradyarrhythmia; each had abnormal sinus node recovery time (greater than 1,400 ms) and abnormal corrected sinus node recovery time (greater than 525 ms) in at least one study. These seven patients also had a significantly prolonged ischemic time (236 +/- 26 versus 159 +/- 68 min, p less than 0.01). In conclusion, cardiac arrhythmias, particularly ventricular tachycardia and bradyarrhythmia, occur more commonly early after orthotopic heart transplantation than has previously been reported. Sinus node dysfunction due to prolonged organ ischemic time, antiarrhythmic drug use or surgical trauma, alone or in combination, may contribute to these arrhythmias.

Permanent and temporary pacemaker implantation after orthotopic heart transplantation

“…Indications for permanent pacing are: sinus node dysfunction (mainly), type II second degree atrioventricular block, and total atrioventricular block. Our data confirmed these findings 4,5,8,12,21,22 .…”

“…Donor sinus node dysfunction is the most common cause of bradyarrhythmia reported after transplantation 4,9,10,20 . Some authors believe that the presence of sinus node dysfunction may be seen as evidence of a worse prognosis after transplantation.…”

“…Local trauma to the superior vena cava, donor age, inadequate denervated heart response to vasoactive amines and previous use of antiarrhythmic drugs, especially amiodarone, may be involved 4,5,8,9,11,12,13,17,23 .…”

“…Cardiac arrhythmias are not uncommon in those who experience denervation after heart transplantation, and temporary pacing might be necessary in the postoperative period [2][3][4][5] . Resting heart rate after transplantation has been shown to be about 100 beats per minute due to the absence of autonomic innervation; however soon after cardiac transplantation, some patients have a lower heart rate at rest [2][3][4][6][7][8] .…”

“…Resting heart rate after transplantation has been shown to be about 100 beats per minute due to the absence of autonomic innervation; however soon after cardiac transplantation, some patients have a lower heart rate at rest [2][3][4][6][7][8] . Bradyarrhythmias occur in more than 50 % of recipients in the immediate postoperative period and are probably due to sinus node dysfunction, but atrioventricular conduction disturbances can also occur in some patients 4,9,10 . The mechanism of these disturbances remains poorly understood although rejection, prolonged ischemic time, specific anomalies of coronary artery anatomy and donor sinus node dysfunction have been suggested 3,9,11,12 .…”