Arrhythmogenic right ventricular cardiomyopathy in young versus adult patients: similarities and differences.

OBJECTIVES: This study was designed to evaluate and compare the patterns of arrhythmogenic right ventricular cardiomyopathy in young people and adults. BACKGROUND: Few data are available on this cardiomyopathy in young people because clinical and morphologic findings considered pathognomonic are normally based on observations in adults. However, a familial occurrence with a probable genetic transmission led to the study of children and to early detection of this disease, in which sudden death has been reported even in young people. METHODS: Seventeen young patients with arrhythmogenic right ventricular cardiomyopathy diagnosed at a mean age +/- SD of 14.9 +/- 4.9 years were studied. Clinical, electrocardiographic, echocardiographic, cineangiographic and biopsy findings were compared with those of 19 adult patients whose condition was diagnosed at a mean age of 38.1 +/- 13.4 years. RESULTS: Syncope occurred in 23.5% of the young patients but in none of the adults (odds ratio of familial sudden death 5.54, p = 0.1). Ventricular couplets (odds ratio 16.0, p = 0.004) and subtricuspid bulging on echocardiography (odds ratio 5.95, p = 0.036) were prevalent in the young group. Cineangiographic data in the two groups were similar, except that more hypokinetic areas were found in adults (odds ratio 4.44, p = 0.05). Morphometric analysis of biopsy sections showed a greater amount of fibrous tissue in the young patients (p = 0.04) and a prevalence of fatty tissue in the adults (odds ratio 12, p = 0.005). During an equivalent follow-up time (mean 7 years), two young patients died suddenly, and two had ventricular fibrillation in the absence of antiarrhythmic therapy. CONCLUSIONS: The pathognomonic criteria for the diagnosis of arrhythmogenic right ventricular cardiomyopathy in adults are also valid for young people. Sudden or aborted death occurred frequently in young untreated patients.

Correlation between cardiac involvement and CTG trinucleotide repeat length in myotonic dystrophy.

OBJECTIVES: Because sudden death due to complete atrioventricular (AV) block or ventricular arrhythmias is the most dramatic event in myotonic dystrophy, we assessed the relation of cardiac disease to cytosine-thymine-guanine (CTG) triplet mutation in adults affected with myotonic dystrophy. BACKGROUND: The myotonic dystrophy mutation, identified as an unstable deoxyribonucleic acid (DNA) sequence (CTG) prone to increase the number of trinucleotide repeats, produces clinical manifestations of the disease in skeletal muscle, the heart and many organ systems. METHODS: Forty-two adult patients underwent electrocardiography and echocardiography; in addition, signal-averaging electrocardiography was performed in 22, and 24-h Holter monitoring was recorded in 32. The diagnosis was established by neurologic examination, electromyography, muscle biopsy and DNA analysis. The patients were then classified into three subgroups on the basis of the number of CTG trinucleotide repeat expansions: E1 = 18 patients with 0 to 500 CTG repeats; E2 = 12 patients with up to 1,000 repeats; E3 + E4 = 10 patients with up to 1,500 repeats and 2 patients with > 1,500 repeats. RESULTS: The incidence of normal electrocardiographic (ECG) results was found to be significantly different in the three subgroups (55%, 50%, 17% in E1, E2, E3, + E4, respectively, p = 0.04), with the highest values in the group with fewer repeat expansions. The incidence of complete left bundle branch block was also significantly different among the groups (5% in E1, 0% in E2, 42% in E3 + E4 p = 0.01) and was directly correlated with the size of the expansion. A time-domain analysis of the signal-averaged ECG obtained in 12 patients in E1, 4 in E2, 5 in E3 and 1 in E4 showed that abnormal ventricular late potentials were directly correlated with CTG expansion (33% in E1, 75% in E2, 83% in E3 + E4, p = 0.05). Moreover, the incidence of ventricular couplets or triplets showed a positive correlation with size of CTG expansion (0 in E1, 0 in E2, 29% in E3 + E4, chi square 0.02). CONCLUSIONS: Our findings suggest that the involvement of specialized cardiac tissue, accounting for severe AV and intraventricular conduction defects, is related to CTG repeat length. In addition, the presence of abnormal late potentials directly correlates to CTG expansion. Abnormal late potentials, caused by slowed and fragmented conduction through damaged areas of myocardium, represent a substrate for malignant reentrant ventricular arrhythmias. In the future, therefore, molecular analysis of DNA should identify patients with cardiac disease at high risk for development of AV block or lethal ventricular arrhythmias.

Acute mitral regurgitation after blunt chest trauma.

We treated a case of isolated acute mitral incompetence due to complete transection of the anterior papillary muscle produced by blunt chest trauma. The excellent results obtained with conservative therapy suggest that this approach be used in other similar cases. The pertinent medical literature is reviewed.

Diagnostic accuracy of right ventriculography in arrhythmogenic right ventricular cardiomyopathy.

Diagnostic sensitivity and specificity of cineangiography were evaluated by multivariate logistic discriminant analysis in 32 patients with arrhythmogenic right ventricular (RV) cardiomyopathy, 27 patients with biventricular dilated cardiomyopathy, 28 patients with atrial septal defect and 18 normal subjects. In patients with arrhythmogenic RV cardiomyopathy and biventricular dilated cardiomyopathy, the diagnosis was confirmed by endomyocardial biopsy. All RV values overlapped for the diagnosis of atrial septal defect and arrhythmogenic RV cardiomyopathy; overlapping extended to dilated cardiomyopathy for end-diastolic volume and infundibular dimensions. RV ejection fraction appeared reduced in all the diseases; in particular, mean values in dilated cardiomyopathy and arrhythmogenic RV cardiomyopathy were 38 and 53%, respectively (p less than 0.05). Left ventricular quantitative studies showed a significant difference between dilated and arrhythmogenic RV cardiomyopathy, both in terms of pumping indexes (mean end-diastolic volumes 180 vs 91 ml/m2 and mean ejection fraction 33 vs 60%), and indexes of contractility (stress/end-diastolic volume 3.7 vs 6.7). Multivariate analysis disclosed that transversally arranged hypertrophic trabeculae, separated by deep fissures, were associated with the highest probability of arrhythmogenic RV cardiomyopathy (p less than 0.001). Posterior subtricuspid and anterior infundibular wall bulgings were the only other independently significant variables. Coexistence of these signs was associated with 96% specificity and 87.5% sensitivity. Thus, arrhythmogenic RV cardiomyopathy presents quantitative volumetric and hemodynamic as well as qualitative features that clearly distinguish it from dilated cardiomyopathy and confirm its nosographic autonomy among the primary diseases of the myocardium.

Late potentials and ventricular arrhythmias in arrhythmogenic right ventricular cardiomyopathy.

We studied 38 patients (mean age 32 +/- 14 years) with arrhythmogenic right ventricular cardiomyopathy (ARVC) to evaluate the clinical significance of histologic features on endomyocardial biopsy specimens as related to signal-averaged electrocardiography (SAECG), spontaneous ventricular arrhythmias, and hemodynamic features. Fifteen patients presented with ventricular tachycardia or fibrillation (sustained ventricular arrhythmias), 23 with other minor arrhythmias. SAECG variables and right ventricular ejection fraction (RVEF) were statistically correlated with the extent of myocardial fibrosis on biopsy in ARVC. An increased percentage of fibrous tissue (> or = 30%) was a significant univariate predictor of late potentials (p = 0.004) and reduced RVEF (p = 0.02). The 18 patients with late potentials had an increased percentage of fibrous tissue (p = 0.01), a reduced RVEF (p = 0.0004), and a higher risk for sustained ventricular arrhythmias (p = 0.05) than the 20 patients without late potentials. RVEF was the most powerful predictor of late potentials (p = 0.004) at multivariate analysis. Moreover, RVEF < or = 50% was associated with an increased risk for development of sustained ventricular arrhythmias (p = 0.02). A SAECG parameter, namely the root-mean-square voltage of the terminal 40 ms at 25 Hz, was an independent predictive factor for the occurrence of sustained ventricular arrhythmias (p = 0.02). Although fibrous tissue may contribute to delayed myocardial activation in ARVC, a reduced RVEF plays an essential role for spontaneous manifestation of sustained ventricular arrhythmias.

Discrete subaortic stenosis. Operative age and gradient as predictors of late aortic valve incompetence.

Between January 1969 and May 1990, 100 patients were operated on for discrete subaortic stenosis. Three patients died in the perioperative period. Patients with intrinsic lesions, prosthetic replacement, or extensive operative remodeling of the aortic valve were excluded from the analysis. The 67 remaining patients had a median follow-up of 62 months. Preoperatively, 8 patients had aortic valve competence, 51 had mild incompetence, and 8 patients moderate aortic valve incompetence. At follow-up mild incompetence persisted in 27 and moderate incompetence in 6 patients. In 1 patient it worsened from no incompetence to mild and in another patient from mild to moderate. The probability of aortic incompetence at follow-up was significantly and simultaneously related (multivariate ordinal logistic model) to (1) older age at operation (logarithm of months, p = 0.007), (2) higher preoperative gradient (third power of milligrams of mercury, p = 0.0004), (3) preoperative cardiomegaly (p = 0.04), and (4) surgical myectomy (p = 0.002). There was an interaction between age and gradient (p = 0.03). Two nomograms are proposed as a generalizable aid to decision making. The data support the policy of early repair of subaortic stenosis.

Does Down syndrome affect prognosis of surgically managed atrioventricular canal defects?

The appropriateness of surgical correction of complete atrioventricular canal defect in patients with Down syndrome has been questioned on a cost-benefit basis. Our experience with nonselective correction of all patients with atrioventricular canal defects gave us the opportunity to evaluate the impact of Down syndrome on postoperative survival. Between January 1, 1975, and December 31, 1989, we operated on 94 patients with Down syndrome and on 127 genetically normal patients. One hundred thirty-four patients had partial or intermediate atrioventricular canal defect (28% Down patients) and 87 had complete atrioventricular canal defect (74% Down patients). Thirty-two patients died perioperatively and 10 patients died during the 15-year follow-up. The actuarial survival was 90% in the genetically normal patients and 57% in patients with Down syndrome (p < 0.0001). Nonetheless, when the confounding effects of pulmonary vascular resistance and the prevalence of more severe anatomic forms in patients with Down syndrome were eliminated with a multivariable analysis in the hazard domain, Down syndrome was not a significant independent incremental risk factor. This was verified by fitting parametric survival to actuarial survival graphically and by a testing of fit. Patients with Down syndrome underwent fewer reoperations and fared as well as or even better, on clinical and echocardiographic investigation, than their genetically normal counterparts.

Surgical management of double-outlet right ventricle.

From 1977 to 1983, 32 consecutive patients, ranging in age from 15 days to 24 years, underwent operations for double-outlet right ventricle. Twenty patients had a palliative operation either to increase (12 cases) or to reduce (eight cases) pulmonary blood flow: Ten of them have subsequently undergone total repair, and in another six correction was delayed because of possible incremental operative risk factors, such as multiple ventricular septal defects or the need for an extracardiac conduit. Four patients with multiple, complex associated intracardiac anomalies are currently considered to have uncorrectable defects. A total of 22 patients underwent correction either primarily (12) or after palliation (10). Intraventricular tunneling was performed in 16 patients with a subaortic ventricular septal defect and in one with a doubly committed ventricular septal defect. Seven of these had pulmonary stenosis and five had reconstruction of the right ventricular outflow by means of a patch (three) or a conduit (two); among this group, five also had enlargement of the ventricular septal defect. In three patients with a subpulmonary defect and in one with a remote ventricular septal defect, all of them without pulmonary stenosis, total repair was achieved by a Senning, a Mustard, or an arterial switch operation. Finally, the only patient with atrioventricular discordance and pulmonary stenosis had insertion of a left ventricle-pulmonary artery conduit. No operative deaths were observed after palliation, but one patient died of intrapulmonary hemorrhage after total repair (4.5%). Major postoperative complications included detachment of the ventricular septal defect patch in one patient and late progression of pulmonary vascular obstructive disease in another. No late deaths have been recorded. Surgical repair of double-outlet right ventricle can be accomplished with gratifying early and late results, the risk of operative death being below 5%. The outcome in patients with subaortic ventricular septal defect appears particularly favorable, despite the extensive intracardiac procedures required for total correction. An early intervention is recommended to prevent development of pulmonary vascular obstructive disease and to avoid massive cardiac hypertrophy and fibrosis, which may cause late rhythm disturbances and impede the intracardiac repair.

Experience with operation for total anomalous pulmonary venous connection in infancy.

Twenty patients presenting with total anomalous pulmonary venous connection (TAPVC) in infancy underwent cardiac repair. Four had associated major intracardiac anomalies (complex TAPVC) and 16 had isolated TAPVC. All patients with complex lesions died during or shortly after the operation; they all had pulmonary venous obstruction (PVO). The associated malformations were critical pulmonary stenosis (one case), multiple ventricular septal defects (VSDs) (one case), mitral atresia (one case), and asplenia syndrome with common atrioventricular valve, double-outlet right ventricle, and pulmonary stenosis (one case). Among the patients with isolated lesions there were two surgical deaths, both in infants less than 1 month of age, with severe PVO and subdiaphragmatic drainage. Statistical analysis of these data shows a strongly incremental risk of surgical death due to the presence of associated malformations. Analysis of just isolated TAPVC shows a possible incremental effect due to neonatal age (less than 1 month) and PVO, these two factors being not clearly separated. There have been no late deaths and no late complications among the 14 survivors followed from 7 months to 10 years (mean 44 months). An aggressive surgical approach regardless of the age, degree of pulmonary hypertension, and type of anatomic connection is advised for isolated TAPVC. Some caution is recommended for complex TAPVC, in which a much higher risk is anticipated, particularly when a palliative pulmonary vein-to-left atrium anastomosis is performed.

Tricuspid atresia versus other complex lesions. Comparison of results with a modified Fontan procedure.

Several modifications of the Fontan principle are currently applied to the treatment of tricuspid atresia with low mortality. The use of these modifications in other malformations has most frequently been associated with less satisfactory results. At our institution, from June 1977 to October 1986, 35 consecutive patients, whose ages ranged from 8 months to 20 years (median age 3.4 years), underwent a modified Fontan procedure. Twenty patients with a median age of 3.2 years (group I) having tricuspid atresia (16 patients) or hypoplastic right heart syndrome (four patients) were treated by means of a right atrium-pulmonary artery anastomosis (12 patients) or right atrium-subpulmonary chamber connection (eight patients). Fifteen patients (group II) with a median age of 3.6 years, having a single left ventricle (10 patients), left atrioventricular valve hypoplasia or atresia (three patients), or double-outlet right ventricle (two patients), underwent right atrium-pulmonary artery anastomosis, together with a repositioning of the atrial septum to the right of the right atrioventricular valve, which thus left intact the inlet to the ventricle(s). The operative mortality rate was 25% in group I and 0% in group II. One patient in group I and one in group II died late postoperatively. All the 28 survivors are free of symptoms 3 months to 9 years after correction. According to our results, low risk can be associated with modified Fontan procedures in the treatment of complex heart malformations other than tricuspid or pulmonary atresia. Preserving the integrity of the entire inlet to the ventricle(s) by repositioning the interatrial septum, as done in group II malformations, might be helpful in improving the quality of the repair.

Long-term results of mitral commissurotomy.

Between January 1968 and December 1989, 280 patients underwent conservative surgical treatment for pure mitral stenosis. Closed commissurotomy was utilized in 134 patients, with a mean age of 38 +/- 11 years and a mean valve area of 1.0 +/- 0.29 cm2. Open commissurotomy was performed in 146 older patients (mean age 44 +/- 11 years) with a mean valve area of 0.9 +/- 0.3 cm2. The perioperative mortality was 3% in closed procedures and 3.4% in open procedures. Surviving patients were evaluated by questionnaires or phone interviews, and 129 patients were examined by two-dimensional echocardiography with the purpose of analyzing long-term results. Follow-up was 95% complete (Grunkemeier-Starr method), with a median of 18 years in patients with closed commissurotomy and 6.6 years in patients with open commissurotomy. The actuarial survival at 21 years was 60.8% (70% confidence limits 55% to 66%) in patients having closed commissurotomies and 60.6% (70% confidence limits 49% to 71%) at 22 years in patients having open commissurotomies. The "effective palliation" rate, defined by clinical and echocardiographic criteria, was 47% at 15 years and 15% at 20 years. We conclude that mitral commissurotomy is the procedure of choice in pure mitral valve stenosis and should be applied early. When performed in patients aged less than 40 years, a 78% (70% confidence limits 72% to 84%) survival at 18 years and 67% "effective palliation" at 15 years were observed. The closed valvotomy results of our study support the present trend toward use of percutaneous balloon valvotomy.

Compositional changes of a dicalcium phosphate dihydrate cement after implantation in sheep.

A hydraulic calcium phosphate cement having dicalcium phosphate dihydrate (DCPD) as end-product of the setting reaction was implanted in a cylindrical defect in the diaphysis of sheep for up to 6 months. The composition of the cement was investigated as a function of time. After setting, the cement composition consisted essentially of a mixture of DCPD and beta-tricalcium phosphate (beta-TCP). In the first few weeks of implantation, the edges of the cement samples became depleted in DCPD, suggesting a selective dissolution of DCPD, possibly due to low pH conditions. The cement resorption at this stage was high. After 8 weeks, the resorption rate slowed down. Simultaneously, a change of the color and density of the cement center was observed. These changes were due to the conversion of DCPD into a poorly crystalline apatite. Precipitation started after 6-8 weeks and progressed rapidly. At 9 weeks, the colored central zone reached its maximal size. The fraction of beta-TCP in the cement was constant at all time. Therefore, this study demonstrates that the resorption rate of DCPD cement is more pronounced as long as DCPD is not transformed in vivo.

Left atrioventricular valve incompetence after repair of common atrioventricular canal defects.

BACKGROUND: Reoperation rate for residual atrioventricular (AV) valve regurgitation after repair of common atrioventricular canal defect (AVCD) is currently between 5% and 10%. This retrospective analysis evaluates the impact of AV valve anatomy, age at repair, and surgical technique on postoperative AV valve incompetence. METHODS: Between January 1982 and July 1994, 205 patients with common AVCD underwent surgical repair at our institution. A complete form with common atrioventricular orifice (CCAVCD) was present in 81 patients. One hundred twenty-four had separate AV valves and orifices; 22 of these had a restrictive ventricular septal defect component. Preoperative moderate to severe AV valve regurgitation (AVVR) was present in 74 (36%), with a lower incidence in the CCAVCD group (20/81, 25%) versus the transitional (8/22, 36%) or the partial forms (46/102, 45%) (p = 0.02). The incidence was 12.5% (3/24) for CCAVCD patients less than 4 months of age (p = 0.02). Repair of the left AV valve was performed according to the trifoliate approach in most cases (142/205, 70%). Follow-up was 98% complete. RESULTS: By Kaplan-Meier analysis, survival at 12.3 years was 97.8% +/- 1% in partial AVCD, 95.4% +/- 4% in transitional AVCD, and 73.2% +/- 5% in CCAVCD (median follow-up, 60 months). Freedom from reoperation at 12.3 years was 93.5% +/- 2% for partial AVCD, 76.9 +/- 9% for the transitional form, and 68.3% +/- 5% for CCAVCD: Postoperative moderate to severe AVVR occurred in 42 patients (21%), with lower incidence for CCAVCD (10/81, 12.5%) versus transitional AVCD (8/22, 36%) and partial AVCD (24/102, 24%) (p = 0.02). Postoperative moderate AVVR was found in only 1 patient with CCAVCD less than 4 months of age (p < 0.01). Nine patients (5%) underwent reoperation for residual postoperative AVVR Valve repair was performed in all with no operative death. By Cox proportional risk multivariate analysis, preoperative AVVR and double orifice "mitral" valve were associated with increased risk of postoperative left AVVR (p < 0.01), whereas a bifoliate approach appeared to reduce the risk of this event in partial AVCD (p = 0.03). CONCLUSIONS: Postoperative AVVR is related to the type of anatomy of the AV valve, to the age at repair, and to the surgical technique employed. Residual AVVR can still be corrected with conservative techniques at low mortality rates. Early repair of common AVCD is associated with a lower incidence of preoperative and postoperative AVVR in CCAVCD and seems to prevent progression of annular dilation and preoperative AVVR in partial AVCD.

Prosthetic replacement of the tricuspid valve: biological or mechanical?

BACKGROUND: Incidence of tricuspid prosthesis replacement was 1.9% of all valvular operations performed between June 6, 1966 and April 18, 1996. Many series report similar figures, but institutional experience is limited and the consensus on treatment modalities is lacking. METHODS: One hundred tricuspid operations were performed on 83 patients (46 female). A primary operation was performed in 64 cases, 13 patients had one previous operation, 4 patients had two previous operations, and 2 patients had three previous operations. Seventeen patients required a tricuspid prosthetic valve rereplacement. There were 2 emergent and 17 urgent operations. The New York Heart Association class was IV in 13 patients (mean pulmonary artery pressure, 41 mm Hg), III in 66 patients (mean pressure, 38 mm Hg), and II in 21 patients. The most frequent operation was simultaneous replacement of the mitral and tricuspid valve (41 patients). Seventy biological and 30 mechanical prostheses were used. Total follow-up time was 613 years, mean 7.4 years (median 4.2 years), with a maximum of 27.8 years, and was 92% complete. RESULTS: Operative mortality was 24%. Survival was 0.54 (0.48 to 0.59, n = 39) at 5 years, 0.38 (0.32 to 0.44, n = 27) at 10 years, 0.31 (0.25 to 0.36, n = 19) at 15 years, 0.29 (0.23 to 0.34, n = 11) at 20 years, and 0.17 (0.098 to 0.26, n = 3) at 25 years. Early mortality was increased from higher New York Heart Association class (hazard ratio = 2.2), congenital disease (hazard ratio = 6.9), and valvuloplasty failure (hazard ratio = 4.3). The constant risk phase (4%/patient-year) after 2 years was enhanced by older operative age (hazard ratio = 1.4). Prosthetic type had no independent effect. Biological prostheses were at risk for 300 years and had a reoperation incidence of 4.7%/ patient-year (14 events); mechanical prosthesis were at risk for 137 years with a rate of 2.2%/patient-year (3 events) (p = 0.21). Three valve thromboses were observed in old-design mechanical prosthesis. Bioprosthetic degeneration showed a steeper rate after 7 years. CONCLUSIONS: This study does not show a clear superiority of biological versus mechanical prostheses. In the long run survival with mechanical prostheses could be superior, given the high rate of bioprosthetic degeneration after 7 years.

Multivariate analysis of survival after malfunctioning biological and mechanical prosthesis replacement.

BACKGROUND: Results of valvular reoperations depend on extrinsic and patients' intrinsic risk factors. New prosthetic substitutes continue to appear and the clinical effect is difficult to evaluate. Randomized studies are limited by patient selection and follow-up time. We followed the patient-centric outcome research applied to a large database of valvular operations. METHODS: Between January 1, 1970 and January 1, 1995 755 patients underwent one reoperation, 96 a second reoperation, and 12 a third reoperation. On January 1, 1996 a common closing date follow-up was obtained in 98.7% of reoperated patients. Multivariable analysis in the hazard domain was applied to obtain an upgradable model of survival that could be used for predictions and treatment comparison. RESULTS: Postoperative death hazard showed an early phase merging within 6 months with a constant low hazard phase. The survival proportion was 0.65 (70% CL, 0.63 to 0.67) at 5 years, 0.51 (70% CL, 0.49 to 0.53) at 10 years, 0.47 (range, 0.44 to 0.49) at 15 years, 0.42 (70% CL, 0.39 to 0.46) at 20 and 25 years. Significant incremental risk factors for early mortality were reoperative era 1970 to 1980 (hazard ratio = 2.8), reoperation number (hazard ratio = 1.9), heart penetration on surgery (hazard ratio = 7.6), emergent operation (hazard ratio = 5.8), urgent operation (hazard ratio = 2.1), prosthetic thrombosis (hazard ratio = 2.4), acute prosthetic endocarditis (hazard ratio = 3.0), acute endocarditis of the natural valve at antecedent operation (hazard ratio = 3.2), original floppy valve pathology (hazard ratio = 3.2), and mitroaortic replacement (hazard ratio = 5.7). Isolated mitral reoperation had a lower risk (hazard ratio = 0.5). Significant incremental risk factors for constant phase were: operative era (1970 to 1980) (hazard ratio = 2.0), congestive heart failure (hazard ratio = 2.6), reoperation on tricuspid valve after previous mitral insertion (hazard ratio = 4.9), reoperation for recurring dehiscence (hazard ratio = 4.6), double-valve procedure (hazard ratio = 1.6), coronary artery bypass graft (hazard ratio = 2.7), aortic root disease at original operation (hazard ratio = 2.1), older operative age (hazard ratio = 1.1). Use of bileaflet prosthesis was found to decrease significantly (p = 0.0002) the death risk (hazard ratio = 0.2). CONCLUSIONS: There is no late uprising hazard, and surviving patients remain exposed to a low risk of death (4% of patients per year). Considering simultaneously the confounding from operative age and operative era and the many concomitant risk factors, survival appears favorably influenced by use of bileaflet valves on reoperation.

Accuracy of electrocardiographic and echocardiographic indices in predicting life threatening ventricular arrhythmias in patients operated for tetralogy of Fallot.

OBJECTIVE: To validate the accuracy of the prognostic significance of non-invasive clinical diagnostic indices as predictors of sustained ventricular tachycardia (sVT) or fibrillation (VF) in patients undergoing repair for tetralogy of Fallot. METHODS: One way analysis of variance and pairwise comparison of the values with the Bonferroni correction, logistic multivariate analysis, and ordinal logistic analysis were used to study quantitative electrocardiographic and echocardiographic variables in 66 patients who had undergone surgery for tetralogy of Fallot by ventriculotomy at a mean (SD) age of 11.8 (9.5) years. The mean (SD) period of follow up was 16.1 (5.7) years after surgery. RESULTS: Four groups of patients were identified by ECG and 24 hour Holter monitoring: 19 (28.7%) without ventricular arrhythmias, 34 (51.5%) with minor ventricular arrhythmias, seven (10.6%) with non-sustained ventricular tachycardia (nsVT), and six (9.0%) with sVT or VF. One way analysis indicated significant differences in QT dispersion (QTd) and end diastolic volume of the right ventricle (EDVRV) among the groups. Univariate logistic analysis showed EDVRV, QTd, and QRS duration to be significantly associated with sVT or VF. Stepwise multivariate analysis and ordinal logistic analysis showed QTd to be preferable to QRS duration as an indicator, because it was unrelated to EDVRV, and was capable of separating different probability curves for nsVT as opposed to sVT or VF. CONCLUSIONS: Stratification of patients undergoing corrective surgery for tetralogy of Fallot and at risk of life threatening arrhythmias is possible by simple and inexpensive means, which provide sensitive and specific indices.

T-wave changes in patients with hemodynamic evidence of systolic or diastolic overload of the left ventricle: a retrospective study on 168 patients with isolated chronic aortic valve disease.

The effect of systolic and diastolic overload of the left ventricle on the T wave was studied in 86 patients with pure aortic stenosis and in 82 patients with pure aortic insufficiency documented by hemodynamic investigation. All patients had hemodynamically significant, chronic isolated aortic valve disease with electrocardiographic evidence of left ventricular hypertrophy (Sokolow index greater than or equal to 45 mm). All had undergone selective coronary angiography. Flattened or negative T waves were present in 44 patients with aortic stenosis (51%) and in 66 (80%) with aortic incompetence. Inversion of the T wave in left ventricular leads was unrelated to the presence of ventricular conduction disturbances or to coronary artery disease or to low cardiac index. It was significantly related to older age (P = 0.0001) and, in patients with aortic incompetence, to the end-diastolic volume (P = 0.04). Digitalis intake was a nonsignificant (P = 0.10) independent variable. These findings suggest that patients with aortic stenosis cannot be distinguished from patients with aortic incompetence by the electrocardiogram and that the theory of Cabrera and Monroy is not valid in this set of patients.

Electrical instability in patients undergoing surgery for atrioventricular septal defect.

Postoperative 24-hour Holter monitoring was performed in 106 patients with atrioventricular septal defect in order to identify the incidence of atrial and ventricular arrhythmias. Of the patients, 72 had separate atrioventricular orifices, including 13 with a small ventricular component to the defect, and 34 patients had a common atrioventricular orifice. Two groups of abnormal patients were found. First, patients with good electrical stability characterized by isolated atrial (9 patients) and ventricular (25 patients) extrasystoles falling in classes I and II of Lown. Second, patients with marked electrical instability characterized in one patient by repetitive atrial extrasystoles, in another by atrial flutter, in 2 by polymorphic ventricular extrasystole and in 8 by couplets or triplets. Electrical instability in individual patients was then compared, by means of logistic regression analysis, with operative, surgical and postoperative variables. There was no incidence of sudden death in our series. After surgical repair, ventricular arrhythmias were more frequent than atrial arrhythmias (33% vs. 10%) and were unrelated to the type of atrioventricular septal defect. Cardiac electrical instability after operation was significantly related to larger operative body size, higher postoperative end diastolic diameter of the right ventricle, larger size of the ventricular septal defect, coexistence of postoperative right bundle branch block and left anterior hemiblock. Conversely, the risk of arrhythmias was reduced by more recent operative data and by greater shortening fraction of the left ventricle.

The risk of surgical treatment of tetralogy of Fallot: an appraisal.

The risk of surgical treatment of tetralogy of Fallot was analyzed with multivariate statistical techniques in a recent surgical series (1975-1983) of 159 corrected and 59 palliated patients. The overall mortality of correction was 12.6% and that of palliation was 15.3%. The significant and independent risk factors that increased the mortality of palliation were the use of a shunt other than the Blalock or its modifications (mostly Waterston) (P = 0.01), and very young age (P = 0.02). Risk factors that increased the mortality of correction were high left over right ventricular pressure ratio (P-RV/LV) (P = 0.02), persistent patency of the arterial duct (P = 0.02), other major associated lesions (P = 0.02), and the use of a transannular patch (P = 0.04). Cardioplegia significantly decreased the risk (P = 0.03). With present techniques, correction can be performed in favorable cases with a mortality approaching zero. Staged procedures neutralized the age related risk of correction, but Blalock shunts carried a mortality rate ranging from 9.5% at 1 month to 1.7% at 12 months of age. This was due to the lack of prostaglandins along with technical faults. Predicted two-stage mortality rates ranged in infants (less than 12 months) from 6.2 to 16% and compared favorably with our observed 27% mortality of primary correction. Our results show that the transannular patch becomes a fully expressed risk only in those patients with restrictive pulmonary arteries or isolated branch stenosis. This is because it decreases the force the right ventricle can generate in maintaining the cardiac output. The chances of survival, when compared with those of patients without transannular patch, are significantly less when the P-RV/LV is between 0.6 and 1.0. We therefore discuss the measures to decrease or neutralize this risk related to insertion of a transannular patch. Among the associated lesions, we discuss briefly the potential for residual right outflow tract stenosis, anomalous origin of the left anterior descending coronary artery and anomalous muscle bundle of the right ventricle.

Dehiscence of aortic valve prostheses: analysis of a ten-year experience.

Up to the end of 1982, reoperation for dehiscence of an aortic prosthesis was necessary in 5% of patients operated on for primary aortic valve replacement in the previous decade at the University of Padova Cardiac Surgery Center. This complication occurred early (median time to diagnosis 4 months) and was associated with an elevated 30-day operative mortality (27%, 70% CL 19-37%). This is probably (P = 0.09) related to preoperative heart failure. The follow-up of the traced surviving patients (92%) indicates a continuing poor prognosis with a 6-year survival rate of only 13.5% (70% CL 5.0-30%). All the events were cardiac related and directly or indirectly connected with the persistence or recurrence of dehiscence that was observed in 72% of the cases. In the face of these results, a retrospective study has been performed to identify, on the basis of the available data, the subsets of patients more prone to develop this complication. Our results suggest that a significant increased risk (P less than 0.001) can be identified in patients presenting with bacterial endocarditis (12.2% rate), in patients with concomitant aneurysm of the ascending aorta (10.9%) and in patients with degenerative regurgitation or severe calcifications of their native valve, with rates of 7.0 and 6.0 respectively. In these situations particular care is required to avoid undue stress on the annular tissue. We also suggest the use of buttressed interrupted sutures.