Catheter Ablation of Focal Atrial Tachycardia Originating From a Donor Heart After Bicaval Orthotopic Heart Transplantation Guided by a Noncontact Mapping System

Abstract

SummaryA 19-year-old man who underwent bicaval orthotopic heart transplantation for idiopathic dilated cardiomyopathy complained of palpitations 2 weeks after the heart transplantation. An ECG revealed paroxysmal atrial tachycardia (AT) with a cycle length of 260 ms and the P wave morphology of the AT was similar to that during sinus rhythm. Echocardiography showed normal contraction. No rejection, vasculopathy, or infection was observed. An electrophysiologic study and catheter ablation guided by a noncontact mapping system were performed due to drug refractory AT. The AT was induced spontaneously by isoproterenol infusion. The activation sequence of the AT exhibited a focal pattern, and the breakout site of the AT into the donor right atrium was just 12 mm below the breakout site of the donor sinoatrial node. Radiofrequency catheter ablation eliminated this AT and resulted in an improvement in the symptoms. (Int Heart J 2012; 53: 146-148) Key words: Atrial tachycardia, Bicaval orthotopic heart transplantation, Catheter ablation, Noncontact mapping system O rthotopic heart transplantation is an established and effective therapy for end-stage heart disease. The bicaval anastomosis method better preserves normal right atrial anatomy and function, may minimize any sinoatrial (SA) node trauma, and minimizes the tachyarrhythmia events. However, we present here an interesting case in which paroxysmal focal AT originating from the donor RA was observed without any rejection, vasculopathy, or infection during the subacute phase after bicaval orthotopic heart transplantation and was successfully ablated guided by a noncontact mapping system. Case ReportA 19-year-old man underwent a bicaval orthotopic heart transplant for idiopathic dilated cardiomyopathy. He had received immunosuppressant drugs and steroid therapy. He began complaining of palpitations 2 weeks after the transplant. An ECG revealed paroxysmal atrial tachycardia (AT) ( Figure 1). The AT exhibited a sudden onset with physical activity and sudden termination. The morphology of the AT exhibited positive P waves in leads II, III, and aVF and was biphasic in lead V1. Echocardiography revealed normal contractions and there were no signs of rejection, vasculopathy, or infection. An electrophysiologic study and catheter ablation were performed due to AT refractory to drugs such as bisoprolol and verapamil. The AT was not induced by programming stimulation, however, an AT with a cycle length of 260 ms was spontaneously induced during isoproterenol infusion and was consistent with the clinical AT. The P wave of the AT was similar to that during sinus rhythm and overdrive atrial pacing and infusion of adenosine transiently suppressed the tachycardia (Figure 2). An Ensite Array was inserted into the right atrium (RA) and its geometry was created. The AT terminated while creating the RA geometry, however, the virtual activation sequence of the AT was recorded by the noncontact mapping system. The acti- vation sequence of the AT exhibited a focal pattern and the b...

Multiple atrial tachycardias after orthotopic heart transplantation: A case report and literature review

“… 2 Table 1 lists the single and serial cases of post-OHT AT ablations guided by 3-dimensional mapping system reported in the literature in the last decade. 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 The majority of ATs in stable OHT patients can be attributed to macroreentrant tachycardia, including CTI-dependent flutter and scar-reentrant AT. 1 , 2 Focal AT can be observed originating in low-voltage or border zones adjacent to biatrial anastomosis suture lines.…”