Peter R. McLaughlin

Pulmonary valve replacement in adults late after repair of tetralogy of fallot : Are We operating too late?

OBJECTIVESnThe purpose of this study is to evaluate right ventricular (RV) volume and function after pulmonary valve replacement (PVR) and to address the issue of optimal surgical timing in these patients.nnnBACKGROUNDnChronic pulmonary regurgitation (PR) following repair of tetralogy of Fallot (TOF) leads to RV dilation and an increased incidence of sudden cardiac death in adult patients.nnnMETHODSnWe studied 25 consecutive adult patients who underwent PVR for significant PR late after repair of TOF. Radionuclide angiography was performed in all at a mean of 8.2 months (+/- 8 months) before PVR and repeated at a mean of 28.0 months (+/- 22.8 months) after the operation. Right ventricular (RV) end-systolic volume (RVESV), RV end-diastolic volume (RVEDV) and RV ejection fraction (RVEF) were measured.nnnRESULTSnMean RVEDV, RVESV and RVEF remained unchanged after PVR (227.1 ml versus 214.9 ml, p = 0.74; 157.4 ml versus 155.4 ml, p = 0.94; 35.6% versus 34.7%, p = 0.78, respectively). Of the 10 patients with RVEF > or = 0.40 before PVR, 5 patients (50%) maintained a RVEF > or = 0.40 following PVR, whereas only 2 out of 15 patients (13%) with pre-operative values <0.40 reached an RVEF > or = 0.40 postoperatively (p < 0.001).nnnCONCLUSIONSnRight ventricular recovery following PVR for chronic significant pulmonary regurgitation after repair of TOF may be compromised in the adult population. In order to maintain adequate RV contractility, pulmonary valve implant in these patients should be considered before RV function deteriorates.

Angiographic classification of the isolated, persistently patent ductus arteriosus and implications for percutaneous catheter occlusion

Abstract A percutaneous catheter technique for permanent closure of the isolated, persistently patent ductus arteriosus (PDA) was first described in 1967. 1 The development of a spring-loaded double foam disc occluder on a miniaturized (8 or 11Fr) delivery system 2 placed transvenously 3,4 has allowed this management approach to become an effective alternative to surgery in infants and children. The recent description of an improved release technique and the application of topical thrombin onto the foam of the occluder may further reduce embolization risk and increase total occlusion rates. 5 Little attention, however, has been given to the variation in anatomy and topology of the isolated PDA and its influence, if any, on the technique of catheter occlusion. This report describes the angiographic appearances of isolated PDA as seen at the time of catheter occlusion, presents a classification of the observed variations and comments on how these may affect the procedure.

Detection of enterovirus RNA in myocardial biopsies from patients with myocarditis and cardiomyopathy using gene amplification by polymerase chain reaction.

Recent molecular studies have suggested that viral myocarditis frequently underlies human congestive cardiomyopathy; however, only moderately sensitive and specific techniques were used. Polymerase chain reaction (PCR) gene amplification is a sensitive, specific technique ideally suited for the diagnosis of viral disease in small tissue samples where low copy numbers of the viral genome may be present. Using PCR and high stringency condition, we screened biopsies taken from 48 patients with clinically suspected myocarditis or dilated cardiomyopathy. Five patients demonstrated positive enteroviral signals by PCR; two of them had myocarditis by pathology, whereas the other three had changes consistent with cardiomyopathy. Four other patients had myocarditis diagnosed by pathology from 3 months to 1 year earlier but were now negative by both PCR and pathology. Both pathology and PCR were negative for active myocarditis in all other patients. Ventricular samples taken from left ventricular myectomy in four additional patients with hypertrophic cardiomyopathy, normal human ventricle samples, and uninfected monkey kidney cells were also negative by PCR. This study supports a link between viral infection and dilated cardiomyopathy in some patients. PCR gene amplification provides a new diagnostic approach to patients with suspected myocarditis.

Sustained Ventricular Tachycardia in Adult Patients Late After Repair of Tetralogy of Fallot

OBJECTIVESnWe sought to determine the features associated with sustained monoform ventricular tachycardia (VT) in adult patients late after repair of tetralogy of Fallot (TOF) and to review their management.nnnBACKGROUNDnPatients with repair of TOF are at risk for sudden death. Risk factors for ventricular arrhythmia have been identified from patients with ventricular ectopic beats because of the low prevalence of sustained VT.nnnMETHODSnFrom a retrospective chart review of patients assessed between January 1990 and December 1994, 18 adult patients with VT were identified and compared with 192 with repaired TOF free of sustained arrhythmia.nnnRESULTSnThere was no significant difference in age at repair, age at follow-up or operative history. Patients with VT had frequent ventricular ectopic beats (6 of 9 vs. 21 of 101), low cardiac index ([mean +/- SD] 2.4 +/- 0.4 vs. 3.0 +/- 0.8) and more structural abnormalities of the right ventricle (outflow tract aneurysms and pulmonary or tricuspid regurgitation) than control patients. Electrophysiologic map-guided operation was performed in 10 of 14 patients who required reoperation. VT has reoccurred in three of these patients. Four patients did not undergo operation (three received amiodarone; one underwent defibrillator implantation). Two patients with VT also had severe heart failure and died.nnnCONCLUSIONSnMost patients with VT late after repair of TOF have outflow tract aneurysms or pulmonary regurgitation, or both. These patients have a greater frequency of ventricular ectopic beats than arrhythmia-free patients after repair of TOF. A combined approach of correcting significant structural abnormalities (pulmonary valve replacement or right ventricular aneurysmectomy, or both) with intraoperative electrophysiologic-guided ablation may reduce the potential risk of deterioration in ventricular function and enable arrhythmia management to be optimized.

Congenitally Corrected Transposition of the Great Arteries in the Adult: Functional Status and Complications

OBJECTIVESnWe sought to assess the clinical outcome, functional status and complications of adult patients with congenitally corrected transposition of the great arteries.nnnBACKGROUNDnCongenitally corrected transposition is a rare form of congenital heart disease, although survival into adult life may be expected. Little information is available on the long-term prognosis of these patients once they have reached adulthood. This study focuses exclusively on patients >18 years old followed up at a single tertiary referral center.nnnMETHODSnThe charts of all patients with a diagnosis of congenitally corrected transposition of the great arteries from the Toronto Congenital Cardiac Centre for Adults since 1985 were reviewed. Data were available for 52 patients, 26 of whom had undergone radionuclide angiography. Mortality, clinical and functional status, surgical procedures and complications were reviewed.nnnRESULTSnThirteen patients (25%) died; age at death was 38.5 +/- 12.5 years (mean +/- SD). The current age of survivors is 32.7 years (range 18.2 to 54.3). Of the survivors, 17 had palliative procedures, and 25 had definitive repair, 11 of whom required reoperation. Left ventricle to pulmonary artery conduit replacement was necessary in seven patients. Eighteen patients have permanent pacemakers, nine of whom developed complete heart block perioperatively. Nine patients developed progressive atrioventricular (AV) block unrelated to operation. Supraventricular arrhythmias occurred in 15 patients. Progressive systemic AV valve regurgitation developed in 10 patients and endocarditis in 6.nnnCONCLUSIONSnCongenitally corrected transposition in the adult patient is not a benign condition. Late complications are common and warrant careful, long-term follow-up.

Determinants of Survival and Length of Survival in Adults With Eisenmenger Syndrome

A retrospective study of adults with Eisenmenger syndrome assessed at a tertiary referral center was performed to identify clinical characteristics and establish prognostic determinants. Mortality and cause of death are reported with baseline clinical data correlated with mortality to identify predictors of death. Clinical events during follow-up, including heart failure, atrial arrhythmia, hemoptysis, and syncope were also reviewed. A total of 109 adults with Eisenmenger syndrome (mean +/- SD age 29 +/- 11 years, 43% men) were followed for a median of 6.3 years. Sixty-six patients (61%) had simple cardiac anatomy (13 atrial septal defect, 43 ventricular septal defect, 10 patent ductus arteriosus). The remainder (43 patients) had complex cardiac anatomy (including atrioventricular septal defect, truncus arteriosus, univentricular heart, and transposition of the great arteries). There were 33 deaths and 9 transplantations during follow-up. Median survival was 53 years. Multivariate Cox regression analysis identified age at presentation (hazard ratio [HR] 0.90), supraventricular arrhythmia (HR 3.44), precordial electrocardiogram voltage (HR 1.61/mV increase), and poor New York Heart Association functional class (HR 2.60) as independent predictors of mortality. There is a large variation in the life expectancy for adults with Eisenmenger syndrome. Baseline characteristics associated with increased mortality include younger age at presentation (associated with complex anatomy), functional class, supraventricular arrhythmia, and an electrocardiogram index for right ventricular hypertrophy.

Endovascular stents in the management of coarctation of the aorta in the adolescent and adult: one year follow up

OBJECTIVES To test the hypothesis that endovascular stents used with dilation of coarctation of the aorta (CoA) improve late outcomes. Balloon dilation for CoA has been limited by concerns over the risk for acute dissection, late restenosis, or aneurysm formation. DESIGN All patients seen with CoA between November 1994 and September 1997 underwent attempted stent implantation. Follow up was obtained for all patients and a subgroup (nu2009=u200918) had repeat catheterisation at a mean (SD) of 1.3 (0.5) years to assess residual gradient and stent-CoA morphology. RESULTS Stents were placed in 27 patients (15 male and 12 female patients, mean age 30.1 (13.1)u2009years), of whom seven had prior surgical coarctectomy and one had a prior balloon dilation. Hypertension was present in 26 patients (mean pressure 164 (26)/86 (13)u2009mmu2009Hg), of whom 16 were on antihypertension drugs. CoA gradients were 46 (20)u2009mmu2009Hg (range 18–106u2009mmu2009Hg) at baseline and 3 (5)u2009mmu2009Hg after the procedure. One patient had a stroke following the procedure; another patient had incomplete dilation and underwent a second procedure. At 1.8 (1) years after the procedure the mean pressure was 130 (14)/74 (11)u2009mmu2009Hg with seven patients on antihypertension treatment. The clinical gradient was 4 (8)u2009mmu2009Hg (range 0–32u2009mmu2009Hg). At follow up angiography, the mean gradient was 4(6)u2009mmu2009Hg, and two patients had a gradient over 10u2009mmu2009Hg. Aneurysms formed in three patients at the dilation site; one patient was referred for surgery. CONCLUSION In this age group stent management for CoA appears to be an effective technique and results in sustained reduction in CoA gradients at early term follow up, but aortic aneurysm was detected in 17% of patients who had repeat angiography.

Late arrhythmia in adults with the Mustard procedure for transposition of great arteries: a surrogate marker for right ventricular dysfunction?

OBJECTIVE To examine the relation between ventricular dysfunction and late clinical arrhythmia in adults who underwent the Mustard procedure for transposition of the great arteries. DESIGN Observational study based on periodic outpatient assessment of biventricular function. SETTING Tertiary referral centre. INTERVENTIONS Analysis of data from 12 lead ECGs, echocardiography, exercise radionuclide ventriculography, and magnetic resonance imaging. MAIN OUTCOME MEASURES Clinical outcome and late onset clinical arrhythmia during follow up. ECG and ventricular function indices obtained before arrhythmia onset were used for analysis. RESULTS 51 patients (mean (SD) age 25.7 (5.0) years) fulfilled entry criteria at a mean of 23.4 (4.0) years after the Mustard procedure. Late arrhythmia occurred in 11 (22%): sustained atrial flutter/fibrillation in 10, ventricular tachycardia in one. Compared with patients who remained arrhythmia free, patients with arrhythmia had longer QRS (129 (26)v 112 (16) ms, pu2009=u20090.01), greater QT dispersion (107 (28) v 51 (24) ms, pu2009<u20090.001), and increased ratio of right to left ventricular end diastolic diameter (2.4 (0.9) v 1.7 (0.7), pu2009=u20090.02), but no difference in wall thickness. Systemic ejection fraction was also reduced in the arrhythmia subgroup (at rest: 34.1 (13)% v 47 (16)%, pu2009=u20090.04; during exercise: 37.8 (12)% v 52 (17)%, pu2009=u20090.03). QRS duration correlated with right ventricular end diastolic diameter (ru2009=u20090.59, pu2009<u20090.001), suggesting a possible mechano-electric relation after the Mustard procedure. QT dispersion was the only predictor of clinical arrhythmia in multivariate analysis. CONCLUSIONS Impaired ventricular function in adults with the Mustard procedure for transposition of the great arteries relates to clinical arrhythmia. Late atrial flutter/fibrillation may be a surrogate marker for ventricular dysfunction, and these patients may also be at risk of ventricular tachycardia.

Right ventricular form and function after percutaneous atrial septal defect device closure

OBJECTIVESnWe sought to assess the right hearts response to percutaneous device closure of moderate sized atrial septal defects (ASDs) in adults over a one-year follow-up period.nnnBACKGROUNDnPercutaneous ASD device closure is a safe and effective means of reducing or eliminating interatrial shunting. The response of the adults right heart to device closure is incompletely understood.nnnMETHODSnForty consecutive patients had 40 device implantations (32 with the CardioSeal implant and 8 with the Amplatzer device). The patients were assessed with echocardiography, chest radiography and electrocardiography before the procedure and at 1, 6 and 12 months.nnnRESULTSnThe mean ASD size was 13+/-4 mm, and the device size ranged from 33 to 40 mm for CardioSeal and 12 to 36 mm for Amplatzer. At one month, heart size (49% vs. 46%), four-chamber right ventricular (RV) size (45 vs. 41 mm), paradoxical septal motion (60% vs. 5%), QRS duration (125 vs. 119 ms), PR interval (181 vs. 155 ms) and echocardiographically determined pulmonary artery systolic pressure decreased significantly and was maintained at 12-month follow-up. At six months, right atrial length decreased from 50 to 47 mm. At one year, 29% of patients had persistent RV enlargement.nnnCONCLUSIONSnRight heart morphology undergoes rapid improvement within one month of defect closure, with associated mechanoelectrical benefit. A small number of patients had persistent RV enlargement or pulmonary hypertension, or both, at one year. Our data support the application of transcatheter methods in achieving excellent hemodynamic and anatomic outcomes.

Intracardiac echocardiography guided device closure of atrial septal defects

OBJECTIVESnThis study was designed to determine the feasibility and accuracy of intracardiac echocardiography (ICE) in guiding percutaneous closure of atrial septal defects (ASD).nnnBACKGROUNDnIntracardiac echocardiography is a novel imaging technique that might be used to guide interventional procedures. The sensitivity and specificity of ICE, compared to standard imaging techniques, in detecting potentially adverse procedural events and guiding remedial action will be an important consideration in its use.nnnMETHODSnIn a prospective study, 24 patients underwent device closure of ASD using ICE as the primary echocardiographic imaging modality. Feasibility was expressed as proportion of cases in which complete diagnostic ICE imaging was achieved. Accuracy was expressed as the percent agreement between ICE and simultaneously performed transesophageal echocardiography (TEE).nnnRESULTSnHigh-quality ICE images were acquired in all patients, though images were limited in two patients with aneurysmal septa. Intracardiac echocardiography successfully guided closure of 24 out of 25 ASDs (96%) in 23 patients. There was close agreement between ICE and TEE in their assessment of device position and the adequacy of septal capture before device release (98%) and in identifying the presence of significant residual shunts. Intracardiac echocardiography detected all potentially adverse events, including four malpositions, and guided appropriate remedial action.nnnCONCLUSIONSnIntracardiac echocardiography guided device closure of secundum ASDs is feasible in the majority of patients and provides diagnostic data comparable to TEE. These data indicate that ICE may be used to guide routine closure of ASDs in adults without the need for TEE and general anesthesia.