Transmission of Donor-Derived Trypanosoma cruzi and Subsequent Development of Chagas Disease in a Lung Transplant Recipient.

Donor infection status should be considered when accepting an organ for transplant. Here we present a case of Chagas disease developing after a lung transplant where the donor was known to be Trypanosoma cruzi antibody positive. The recipient developed acute Trypanosoma cruzi infection with reactivation after treatment. Chagas disease-positive donors are likely to be encountered in the United States; donor targeted screening is needed to guide decisions regarding organ transplant and posttransplant monitoring.

Venovenous extracorporeal membrane oxygenation in patients with atrial septal defects.

Two patients presented in profound respiratory distress unresponsive to maximal support and were placed on venovenous ECMO. Subsequently, both were found to have a patent foramen ovale and high pulmonary artery pressures, resulting in a right to left shunt. Both patients had a better than expected response to ECMO, likely related to their shunts allowing oxygenated blood to bypass the high pulmonary artery pressures and go directly to the left heart. Both patients were successfully weaned from ECMO and discharged to home in good condition.

Endoscopic repair of bronchial dehiscence after lung transplantation.

We report a case of bronchial dehiscence after right single lung transplantation and describe a novel means of management: bronchoscopic closure of the defect with alpha-cyanoacrylate glue.

Preliminary experience with minilaparotomy aortic surgery.

This prospective nonrandomized study assessed clinical outcomes of a minilaparotomy technique (MLT) used for elective graft repair of infrarenal aortic aneurysm (AAA) and/or aortoiliac occlusive disease (AIOD). Twenty-three patients requiring infrarenal AAA or aortofemoral bypass underwent a small periumbilical midline incision, nondisplacement of the small bowel, and a traditional vascular anastomosis. Results from these procedures were compared with those from contemporaneous procedures performed in the standard transabdominal (STA) fashion (n = 21). Age, weight, and comorbid conditions were comparable between groups. Patients requiring concomitant renal, mesenteric, or infrainguinal revascularization were excluded. Operating time, length of stay in the intensive care unit (ICU), number of oral feeding times, and length of hospital stay were recorded. There were no significant differences in age, operative time, or aneurysm size between the MLT and STA groups. With the MLT then were significant decreases in ICU stay (1 vs. 1.8 days), length of time to return to a general diet (3 vs. 4.7 days), and length of stay (4.9 vs. 7.3 days.) Morbidity and mortality were not statistically different between groups. Patients undergoing the MLT have reduced ICU and hospital stay, and decreased post operative ileus. The MLT does not increase operating room costs or require expensive laparoscopic equipment or the extended postoperative radiographic surveillance needed after endovascular repair.

Pulmonary veins-left atrial junction: anatomic and histological study.

Pulmonary veins (PVs) are the target of ablation procedures to cure paroxysmal atrial fibrillation (PAF). There are few anatomic and histological studies of PVs. Sixteen human hearts were obtained from autopsies performed at our hospital and cadavers from a local medical school. The anatomic relationship between the PVs and the left atrium (LA) was categorized according to the spatial orientation of the veins within horizontal and vertical planes viewed from the dorsal aspect of the LA. The PVs were sectioned longitudinally, and the sections were stained with hematoxylin and eosin. In addition, selected sections were stained with antismooth muscle antibodies (vessel wall), antipankeratin, and antimyoglobin antibodies (myocardium). The PV-LA junction has variable orientations. Confluent superior and inferior veins, observed in 25% of the hearts, were more common on the left side. A myocardial sleeve extended from the LA onto the adventitial surface of the PV. The sleeve was distinct from the smooth muscle in the PV media, from which it was separated by loose fibrous strands. There was no microscopical boundary between the PV and the LA endocardium. The PV join the LA at variable angles. Each PV is surrounded by a myocardial sleeve extending from the LA.

Complications of dual chamber pacemaker implantation in the elderly. Pacemaker Selection in the Elderly (PASE) Investigators.

Pacemakers are frequently implanted, yet accurate prospective data on implant complications are limited. Elderly patients may be at increased risk of implant complications and are increasingly being referred for pacemaker implantation. The purpose of the present analysis was to define the incidence and possible predictors of serious complications of dual chamber permanent pacemaker implantation in the elderly. Therefore, we sought to prospectively identify the incidence and predictors of pacemaker implant complications in a large multicenter trial involving patients receiving a dual chamber pacemaker. The Pacemaker Selection in the Elderly (PASE) study was a prospective trial designed to evaluate quality of life in dual chamber pacemaker recipients age 65 years or older randomized to DDDR versus VVIR programming. In addition to being age 65 years or older, patients enrolled in this study were in normal sinus rhythm, and had standard indications for permanent pacemaker implantation. All patients received dual chamber pacemakers and were randomized to DDDR versus VVIR pacing. Pacemaker implant complications were collected on standardized forms which were completed at pacemaker implantation and during follow-up appointments. In this study of 407 patients, there were 26 complications occurring in 25 patients (6.1%). The most frequent complication was lead dislodgment which occurred in 9 patients. This was followed by pneumothorax (8 patients) and cardiac perforations (4 patients). In 18 patients (4.4%) repeat surgical procedures (including chest tubes) were required. Complications were noted prior to discharge in only 18 patients. There were no significant predictors of overall complications. Pneumothorax was more frequent in patients > or = 75 years old, and was observed only in patients with subclavian venous access. In conclusion, complications from pacemaker implantation in the elderly are seen in 6.1% of patients and 4.4% of patients require a repeat surgical procedure. Other than advanced age and lower weight predicting for pneumothorax, there are no significant clinical predictors of complications.

Two-staged biatrial linear and focal ablation to restore sinus rhythm in patients with refractory chronic atrial fibrillation: procedure experience and follow-up beyond 1 year.

Recent observations regarding the mechanisms of chronic atrial fibrillation (CAF) plus a few encouraging clinical reports have created a paradigm shift regarding treatment strategies and the potential for restoring normal sinus rhythm (NSR) utilizing available catheter-based ablation techniques. The initial and late follow-up clinical experience with a two-staged biatrial linear and focal radiofrequency ablation (BALF I, II) procedure to restore NSR in patients with CAF are described. Pre-BALF management included confirming drug refractoriness and optimizing anticoagulation therapy. BALF I and II were preceded by transesophageal echocardiography to exclude thrombus. Femoral venous catheters were placed in the left atrium and the right atrium with extensive left atrial mapping, ablation (linear and focal) and more limited right atrial ablation. Localized electrogram recordings demonstrated rapid, localized, stable focal driving rotors (FDRs) in the left atrium (nine patients) and in the right atrium (one patient). Atrial or intraatrial tachycardia (IAT) commonly recurred after BALF I. BALF II addresses these recurrences by repeat mapping and ablation techniques. There were no thromboembolic complications. Two patients developed pericardial tamponade that responded to medical management. Of the 11 patients with late follow-up data, 9 have NSR, atrial function, and are no longer experiencing CAF. Left atrial ablation lines decrease continuous electrogram activity, probably isolate portions of the atrium, and unmask FDRs. Focal and linear ablations appear helpful in transforming CAF to NSR. FDRs are commonly localized to pulmonary vein ostium, trabeculated portions of the atrium, and left atrial appendage.

Clinical presentation of endocardial pacing lead malfunction.

This study highlights the wide spectrum of manifestation of pacing lead malfunction. Patients judged to be pacer dependent or in whom ventricular lead malfunction is suspected, and patients with severe symptoms before pacemaker implantation, should be considered at high risk for the development of hemodynamic compromise; prompt hospital admission and pacing lead replacement should be performed.

Long-term follow-up of heart transplant recipients requiring permanent pacemakers.

BACKGROUND: Permanent pacemaker implantation after heart transplantation is contentious. Indications for these devices in this population are uncertain. The goals of this project were to (1) analyze the time course of donor sinus node dysfunction and atrioventricular block after heart transplantation; (2) evaluate which selected parameters (donor age, ischemic time, heart rate before pacer insertion, and number of rejection episodes) might relate to persistent permanent pacing need, and (3) assess pacemaker complications during follow-up. METHODS: A retrospective analysis of pacemaker implantations (22 cases) was performed in 286 consecutive heart transplantations performed between February 1984 and April 1994 at The Methodist Hospital and Baylor College of Medicine, Houston, Texas. RESULTS: Permanent pacemakers were inserted early after transplantation in 19 patients (mean 24 days); 14 pacemakers were for sinus node dysfunction (bradycardia in five, sinus arrest with junctional escape in eight, and optimization of hemodynamics in one). Symptomatic complete heart block prompted insertion late in two patients (3 and 47 months), and symptomatic sinus pause was the indication for late insertion in one. Recipient mean age was 52.4 years, with mean donor age 29.7 years in patients with pacemakers. By 3 months, 13 of 19 patients receiving pacemakers early (mean preinsertion heart rate 58.3 beats/min) became pacer independent with subsequent mean intrinsic heart rate of 97 beats/min. Recipient or donor age, ischemic time, and rejection episodes did not appear related to long-term pacing need early or late after transplantation. CONCLUSIONS: Inferences from these observations include the fact that many patients with early sinus node dysfunction and bradycardia are not pacer dependent at 3 months. However, those with atrioventricular block early appear to require long-term pacing support. However, the possibility that more aggressive and long-term oral chronotropic medication use after transplantation would obviate early permanent pacemaker need is not addressed. Finally, prospective clinical trials are necessary to precisely characterize benefit of permanent pacemakers and define optimal pacing modes after heart transplantation.

Radiofrequency catheter ablation for management of symptomatic ventricular ectopic activity.

OBJECTIVES: This study assessed the useful role of intracardiac mapping and radiofrequency catheter ablation in eliminating drug-refractory monomorphic ventricular ectopic beats in severely symptomatic patients. BACKGROUND: Ventricular ectopic activity is commonly encountered in clinical practice. Usually, it is not associated with life-threatening consequences in the absence of significant structural heart disease. However, frequent ventricular ectopic beats can be extremely symptomatic and even incapacitating in some patients. Currently, reassurance and pharmacologic therapy are the mainstays of treatment. There has been little information on the use of catheter ablation in such patients. METHODS: Ten patients with frequent and severely symptomatic monomorphic ventricular ectopic beats were selected from three tertiary care centers. The mean frequency +/- SD of ventricular ectopic activity was 1,065 +/- 631 beats/h (range 280 to 2,094) as documented by baseline 24-h ambulatory electrocardiographic (ECG) monitoring. No other spontaneous arrhythmias were documented. These patients had previously been unable to tolerate or had been unsuccessfully treated with a mean of 5 +/- 3 antiarrhythmic drugs. The site of origin of ventricular ectopic activity was accurately mapped by using earliest endocardial activation time during ectopic activity or pace mapping, or both. RESULTS: During electrophysiologic study, no patient had inducible ventricular tachycardia. The ectopic focus was located in the right ventricular outflow tract in nine patients and in the left ventricular posteroseptal region in one patient. Frequent ventricular ectopic beats were successfully eliminated by catheter-delivered radiofrequency energy in all 10 patients. The mean number of radiofrequency applications was 2.6 +/- 1.3 (range 1 to 5). No complications were encountered. During a mean follow-up period of 10 +/- 4 months, no patient had a recurrence of symptomatic ectopic activity, and 24-h ambulatory ECG monitoring showed that the frequency of ventricular ectopic activity was 0 beat/h in seven patients, 1 beat/h in two patients and 2 beats/h in one patient. CONCLUSIONS: Radiofrequency catheter ablation can be successfully used to eliminate monomorphic ventricular ectopic activity. It may therefore be a reasonable alternative for the treatment of severely symptomatic, drug-resistant monomorphic ventricular ectopic activity in patients without significant structural heart disease.

Clinical investigation of antiarrhythmic devices. A statement for healthcare professionals from a joint task force of the North American Society of Pacing and Electrophysiology, the American College of Cardiology, the American Heart Association, and the Working Groups on Arrhythmias and Cardiac Pacing of the European Society of Cardiology.

The goal of radiofrequency catheter ablation and the criterion for efficacy is the elimination of arrhythmogenic myocardium. The application of radiofrequency current in the heart clearly results in lower morbidity and mortality rates than thoracic and cardiac surgical procedures in general, and comparisons of therapy with radiofrequency catheter ablation and therapy with thoracic and cardiac surgical procedures in randomized clinical trials is unwarranted. Trials of radiofrequency catheter ablation versus medical or implantable cardioverter-defibrillator therapy may be indicated in certain conditions, such as ventricular tachycardia associated with coronary artery disease. Randomized trials are recommended for new and radical departures in technology that aim to accomplish the same goals as radiofrequency catheter ablation. Surveillance using registries and/or databases is necessary in the assessment of long-term safety and efficacy.

NASPE/ACC/AHA/ESC medical/scientific statement special report--clinical investigation of antiarrhythmic devices: a statement for healthcare professionals from a Joint Task Force of the North American Society of Pacing and Electrophysiology, the American College of Cardiology, the American Heart Association, and the Working Groups on Arrhythmias and Cardiac Pacing of the European Society of Cardiology.

The goal of radiofrequency catheter ablation and the criterion for efficacy is the elimination of arrhythmogenic myocardium. The application of radiofrequency current in the heart clearly results in lower morbidity and mortality rates than thoracic and cardiac surgical procedures in general, and comparisons of therapy with radiofrequency catheter ablation and therapy with thoracic and cardiac surgical procedures in randomized clinical trials are unwarranted. Trials of radiofrequency catheter ablation versus medical or implantable cardioverter defibrillator therapy may be indicated in certain conditions, such as ventricular tachycardia associated with coronary artery disease. Randomized trials are recommended for new and radical departures in technology that aim to accomplish the same goals as radiofrequency catheter ablation. Surveillance using registries and/or databases is necessary in the assessment of long-term safety and efficacy.

Effects of internal defibrillation on an implanted pacing system with programmable polarity.

Management of multiple cardiac arrhythmias in some patients with both an implantable cardioverter defibrillator (ICD) and a pacemaker has demonstrated several advantages. In such circumstances, it is imperative that pacemaker function and its programmed parameters be preserved following a defibrillation shock. This article describes the effects encountered by a specific programmable polarity pacemaker (RelayR 294-03) when subjected to electrical defibrillation in a canine model. Three pacemakers were repeatedly tested in three separate dog experiments. Each pacemaker, with its leads implanted in the right atrium and the right ventricle, was subjected to a minimum total number of 24 high energy biphasic and monophasic shocks (600-700 V) delivered by a coexisting ICD system using three different defibrillating lead configurations. None of the pacemaker systems showed any failure in function; all pacemakers continued to function within preshock specification and conversion to unipolar pacing and/or backup mode was not observed in any of the tests. Intracardiac electrical potentials measured directly off the ICD and the pacemaker leads, during a defibrillation shock (mean 566.6 V; 23.7 J), showed that potentials measured in a bipolar configuration (tip-ring: mean 21.0 V in atrium, 12.0 V in ventricle) were significantly less than potentials measured in a unipolar configuration (tip-can: mean 387.9 V in atrium, 394.0 V in ventricle; ring-can: mean 405.6 V in atrium, 395.4 V in ventricle). Our compatibility tests demonstrate that use of this programmable-polarity pacemaker in concert with an ICD system appears to be safe. Testing similar to the present study should be conducted prior to complete clinical acceptance of combined ICD and pacemaker implantation.

Nonthoracotomy- versus thoracotomy-implantable defibrillators. Intention-to-treat comparison of clinical outcomes.

BACKGROUND: Nonthoracotomy-implantable cardioverter/defibrillator (ICD) systems may represent a significant advance in the treatment of patients with life-threatening ventricular arrhythmias, but their merits relative to those of the well-established thoracotomy systems remain largely unknown. The objective of this study was to compare the short- and long-term clinical outcomes after attempted ICD implantation via a nonthoracotomy versus thoracotomy approach in similar groups of patients. METHODS AND RESULTS: Between September 1990 and December 1992, 212 consecutive patients underwent attempted ICD system implantation without concomitant cardiac surgery at a single institution. Approach selection was not randomized but rather was based primarily on hardware availability. Primary comparisons of short- and long-term outcome were performed according to the "intention-to-treat" principle. Implantation was attempted via a nonthoracotomy approach in 120 patients (57%) and via a thoracotomy approach in 92 patients (43%). Prior cardiac surgery was more prevalent in the nonthoracotomy patients; otherwise, groups did not differ significantly in terms of prognostically relevant clinical characteristics. Nonthoracotomy implantation was successful in 101 patients (84%). After crossover to thoracotomy implantation (14 patients), the eventual success rate for ICD system implantation was 96% in the nonthoracotomy group. Thoracotomy implantation was successful in 89 patients (97%). Operative mortality was 3.3% in the nonthoracotomy and 4.3% in the thoracotomy groups (P = .73). Nonthoracotomy group patients were less likely to experience postoperative congestive heart failure (6% versus 16%; P = .02) or supraventricular arrhythmia (6% versus 18%; P = .004) and had significantly shorter postoperative intensive care and total hospitalization. Total hospital costs were significantly lower in the nonthoracotomy group ($32,205 versus $37,265; P = .001). After a follow-up of 16 +/- 9 months, there were 17 deaths in the nonthoracotomy group (none sudden) and 12 deaths in the thoracotomy group (1 sudden). One- and 2-year Kaplan-Meier survival probabilities were .87 (95% CI, .78 to .91) and .80 (95% CI, .68 to .88) in the nonthoracotomy group and .90 (95% CI, .82 to .95) and .87 (95% CI, .77 to .93) in the thoracotomy group (P = .56; log-rank test). CONCLUSIONS: Nonthoracotomy ICD implantation is associated with reduced surgical morbidity, postoperative hospital care requirement, and hospital costs and has similar efficacy in preventing sudden death relative to the thoracotomy approach. From these nonrandomized data, it appears that a nonthoracotomy approach should be considered preferable in most patients requiring ICD therapy.

Report of the NASPE Policy Conference on antibradycardia pacemaker follow-up: effectiveness, needs, and resources. North American Society of Pacing and Electrophysiology.

On May 4-5, 1993, a policy conference was held in San Diego, California, under the sponsorship of the North American Society of Pacing and Electrophysiology (NASPE) to identify the fundamental goals of antibradycardia pacemaker follow-up, evaluate the effectiveness with which it achieves those goals, and formulate specific recommendations as to how it can be made more effective. The conference addressed clinical, administrative, and educational objectives, focusing on existing and potential resources for follow-up testing and the appropriate frequency of their application. The training of physicians and associated professionals engaged in follow-up also was addressed, as were regulatory and reimbursement issues. This report summarizes the conclusions and recommendations arrived at during the conference and subsequently approved by the NASPE Board of Trustees.