Prognosis of transient atrioventricular conduction disturbances complicating open heart surgery for congenital heart defects

Two patients who had open heart correction of ventricular septal defect and atrioventricular canal in 1956 and 1958, respectively, had recurrences of high degree heart block several years after an episode of transient dysrhythmia in the immediate postperfusion period. As a result of these observations, we chose to review our surgical experience during a period when adequate electrocardiographic observations and follow-up studies were available.

A total of 911 patients less than 15 years of age had had open heart surgical correction of tetralogy of Fallot, ventricular septal defect or atrioventricular canal from 1960 through 1967. Of the 71 surviving patients who had transient complete heart block, second degree heart block, or atrioventricular dissociation immediately after surgery, 59 could be traced, and only 1 patient (with transient atrioventricular dissociation) had return of the dysrhythmia.

During this period, 7 patients had persistent complete heart block after leaving the operating room, and electronic pacing was instituted. Five died within 24 hours after surgery, and the remaining 2 died soon after discharge.

The study revealed that the risk of recurrence of transient postoperative high degree heart block or atrioventricular dissociation is low, and the prognosis for patients with sinus rhythm after such an episode is favorable.     

Survival in patients with intraventricular conduction defects

All 42,000 electrocardiograms taken at the University of Oregon Health Sciences Center from 1969 through 1971 were reviewed; 325 patients (0.77%) had left bundle-branch block (LBBB) or right bundle-branch block (RBBB) with axis deviation (AD). In December 1974, 90% were contacted or found to be dead. The five-year survival rate (actuarial technique) (mean +/- SE) was 45.5 +/- 2.9%. It was significantly worse than that of age- and sex-matched "controls." In most patients the cause of death could not be determined. Survival of 164 LBBB patients (40.7 +/- 4.1%) at five years was not significantly worse than that of 161 RBBB and AD patients (49.5 +/- 4.2%). Those with syncope did no worse in terms of survival than did those without. The five-year survival in coronary artery disease patients was 33.7 +/- 4.4%, in those with primary conduction system disease (20% of patients), it was 50.6 +/- 6.6%. It will be necessary to know the causes of death and of syncope in conduction disease patients before it can be determined whether or not pacemakers can prevent either.     

Myocardial asynchrony in patients with postinfarction intraventricular conduction defects

BACKGROUND: Postinfarction intraventricular conduction defects lead to asynchronous activation of the myocardium.Hypothesis: The aim of the current study is to evaluate contraction asynchrony in postinfarction patients with intraventricular conduction defects. METHODS: A total of 158 patients 6 months postmyocardial infarction and 15 healthy subjects underwent echocardiography to evaluate atrioventricular, interventricular, intraventricular asynchrony, and myocardial performance index (MPI). A subgroup of 126 patients had intraventricular conduction defects in ECG, whereas 32 with normal QRS complex served as controls. RESULTS: All patients postmyocardial infarction showed intraventricular asynchrony and markedly higher MPI. Comparing groups with and without intraventricular conduction defects postmyocardial infarction, those with left bundle branch block (BBB) had significantly higher parameters of all asynchrony types; those with right BBB and left posterior hemiblock (LPH) had significantly higher interventricular asynchrony parameters; those with left anterior hemiblock did not show significant differences in asynchrony parameters as compared with subjects without postinfarction conduction defects. CONCLUSIONS: (1) Patients 6 months postmyocardial infarction show intraventricular asynchrony and markedly higher MPI. (2) Postinfarction patients with LBBB have the highest parameters of atrioventricular, interventricular and intraventricular asynchrony as compared with postinfarction patients with other and without conduction defects. (3) In postinfarction patients with RBBB or LPH parameters of interventricular asynchrony are significantly higher as compared with postinfarction patients without intraventricular conduction defects.     

Coronary artery disease in patients with congenital heart defects

The prognosis of patients with congenital heart defects has improved significantly: more and more patients reach adulthood and old age. At the same time, the possibility of cardiovascular morbidity increases. The conventional risk factors for coronary artery disease are at least as high or even higher in patients than in the general population. Obesity and sedentary life style are more common in adults with congenital heart defect (ACHD) than in general population. In some patients, for example those with coarctation of the aorta or patients with operated coronary arteries in the infancy, the incidence of coronary artery disease (CAD) is clearly increased. In some patients with cyanotic heart defects (e.g. Fontan), the incidence of CAD might be lower, but it usually returns to the average level or higher after correction of the defect. Coronary artery disease is one of the most important reasons for mortality also in ACHD patients, and the consequences of a coronary event might be more fateful in a patient with a corrected congenital heart defect than in her/his peer. There should be a paradigm shift from operative mortality and short‐term outcome to long‐term morbidity and prevention of cardiovascular disease – a task that often has been forgotten during follow‐up visits.     

Transmural atrial pacing in patients with postoperative congenital heart disease

INTRODUCTION: Some patients with postoperative congenital heart disease require permanent cardiac pacing, but the use of transvenous or epicardial pacing leads may be limited by type of cardiac malformation, venous connections, body size, or fibrosis. Transmural atrial pacing may provide an alternative in difficult patients, but to date has been described in only a few articles with small patient numbers, and data from lead performance are lacking. METHODS AND RESULTS: Records were reviewed in 18 consecutive patients (4 months to 21 years old) with postoperative congenital heart disease receiving transmural atrial pacing leads from July 1994 to December 1996. Implantation materials and techniques were described. Lead sensing and capture thresholds obtained acutely and during short-term follow-up (mean: 11.0 months) were evaluated, and comparisons were made between patients with postoperative Fontan anatomy and non-Fontan patients, and between patients receiving steroid-eluting and nonsteroid leads. Overall, the median acute sensing and capture thresholds of transmural leads were 4.1 m V and 0.7 V at 0.5 msec, respectively. Median follow-up thresholds were 2.8 m V and 0.8 V, respectively. Performance of leads in Fontan patients was similar to those in non-Fontan patients. Steroid-eluting leads had a chronic capture threshold of 0.6 V versus 0.9 V for nonsteroid leads (P = 0.038). CONCLUSION: Transmural atrial pacing leads were successfully implanted in patients with diverse ages and types of postoperative congenital heart disease. Lead performance was acceptable both acutely and during the first year of follow-up.     

复杂性先天性心脏病手术后乳糜胸的治疗体会

目的:探讨先天性心脏病手术后乳糜胸的原因及治疗。方法:回顾性分析总结我院2000年10月至2005年3月期间先天性心脏病手术后乳糜胸16例临床资料。结果:16例先心病手术后乳糜胸患者中15例为手术中不同程度的损伤胸导管或其分支所致,经持续胸腔引流、胃肠禁食、静脉内营养等保守治疗后,仅1例在术后10天内因胸腔引流量持续大于10 ml／kg·d,而再次手术结扎胸导管,其余15例均由保守法治疗治愈(93．7％)。结论:先天性心脏病手术后并发的乳糜胸经保守治疗多可痊愈。     

Biventricular pacing in patients with heart failure and intraventricular conduction delay

In patients with advanced chronic heart failure, characterized by prolonged QRS duration and by decreased cardiac contractility, decreasing dysynchrony by biventricular pacing seems to improve exercise tolerance (6-min walk distance), symptoms (New York Health Association class), and quality of-life scores. Although the results of several reports were consistent, the numbers of patients studied were small, and many of the changes were trends that did not reach statistical significance. The availability of a non-pharmacological treatment that improves exercise capacity and quality-of-life would be a major advance. However, further studies will need to address the question of mortality and morbidity benefits of such intervention.     

Covered stents in patients with congenital heart defects.

OBJECTIVES: To evaluate the role of covered Cheatham-Platinum stents in patients with congenital heart disease. BACKGROUND: There are limited data in the literature about the use of covered stent in patients with congenital heart disease. METHODS: Between January 2004 and September 2005, covered Cheatham-Platinum stents were implanted into 18 patients with congenital heart defects (9 males, median age 19 years, range 8-45 years). Sixteen had aortic coarctation or recoarctation (8 with associated aneurysm, 1 with patent ductus arteriosus, 3 with an irregular wall, 4 with subatretic native aortic coarctation) (group 1). Two subjects with univentricular heart circulation were treated because of complex right-to-left shunting (Group 2). RESULTS: Group 1: The stents used ranged from 34 to 45 mm in length. The mean fluoroscopy and procedure times were 12+/-8 and 70+/-15 minutes, respectively. After implantation, the gradient across the stenosis decreased significantly (prestent median value 37 mmHg) (range 20-50 mmHg) versus poststent: median value 0 mmHg (range 0-10 mmHg) (P<0.0001). Vessel diameter increased from a median value of 6 mm (range 0-11) to a median value of 14 mm (range 10-23) (P<0.0001). Stents were placed in the correct position in all subjects. No complications occurred and on angiographic control the stenoses had been relieved and the aneurysms completely excluded. Group 2: Implantation of the covered stents successfully abolished right-to-left shunting in both patients. Both had significant increases in oxygen saturation and no complications occurred. Follow-up: During a median follow-up of 7 months (1-19 months), the results were stable without any complications. CONCLUSION: Covered Cheatham-Platinum stents are very useful tools for treating various congenital cardiovascular malformations.     

Prognostic implications of intraventricular conduction defects in patients undergoing stress echocardiography for suspected coronary artery disease

PURPOSE: To investigate the prognostic implications of conduction defects in subjects without proven coronary artery disease who had been referred for stress echocardiography. METHODS: The study sample consisted of 1230 patients (574 men and 656 women; mean [+/- SD] age, 63 +/- 10 years) who underwent stress echocardiography with dipyridamole (n = 780) or dobutamine (n = 450) to evaluate suspected coronary artery disease. A summary wall motion score (on a 1 to 4 scale) was calculated. Patients were followed for a mean of 41 +/- 27 months; mortality was the only endpoint. RESULTS: Four hundred and twenty patients (34%) had intraventricular conduction defects on a resting electrocardiogram (173 with complete left bundle branch block, 98 with isolated right bundle branch block, 43 with right bundle branch block with left anterior hemiblock, and 106 with left anterior hemiblock). Ischemia at stress echo (new or worsening of preexisting wall motion abnormality) was found in 250 patients (20%). There were 56 deaths during follow-up; 138 patients underwent revascularization and were censored. Multivariate predictors of mortality were resting wall motion score index (hazard ratio [HR] = 6.0 per unit increase; 95% confidence interval [CI]: 2.3 to 16; P <0.0001), ischemia at stress echo (HR = 3.9; 95% CI: 2.2 to 6.7; P <0.0001), age >65 years (HR = 3.2; 95% CI: 1.7 to 5.9; P <0.0001), hypertension (HR = 1.8; 95% CI: 1.1 to 3.2; P = 0.03), and right bundle branch block with left anterior hemiblock (HR = 3.7; 95% CI: 1.8 to 7.5; P <0.0001). The other three forms of intraventricular conduction defects (left bundle branch block, isolated complete right bundle branch block, and left anterior hemiblock) were not associated with mortality in multivariate analyses, or among the 980 patients who did not have ischemia. CONCLUSION: Right bundle branch block with left anterior hemiblock is an independent predictor of mortality in patients with suspected coronary artery disease undergoing stress echocardiography, whereas isolated right bundle branch block is associated with outcomes similar to those observed in patients with no conduction defects.     

A novel approach to eliminate intraventricular lead placement in patients with congenital heart disease

Purpose

We describe two patients with congenital heart disease who were referred for implantable cardioverter-defibrillator (ICD) placement. Both patients possessed factors causing the conventional transvenous approach to be undesirable. We therefore devised a technique which circumvented both intravascular ICD lead placement, as well as placement of leads across the tricuspid valve.

Methods

For both patients, a bipolar pace?Csense lead was successfully placed in a branch of the coronary sinus. A shocking coil was then tunneled from the posterolateral margin of the device pocket, being positioned posterior and inferior to the cardiac silhouette. Defibrillation testing was carried out with goal of a 10-J safety margin.

Results

We were able to successfully achieve ICD implantation in both patients with complex congenital heart disease without requirement for surgical thoracotomy or a lead across the AV valve. R waves in excess of 5?mV were obtained and acceptable defibrillation characteristics were achieved. Both patients are doing well after mid-term follow-up.

Conclusion

A new implant approach is presented, which involves minimal intravascular hardware and eliminates passage across the atrioventricular valve for patients with congenital heart disease in whom conventional ICD implant techniques may be undesirable or not possible. This procedure is technically straightforward with proper technique and knowledge of the patient specific anatomy.     

Haemostatic defects in cyanotic congenital heart disease.

An investigation of defects of the haemostatic mechanism in 41 children with cyanotic congenital heart disease concluded that such abnormalities were common and normally involved factors synthesised in the liver, that is the vitamin K dependent factors (rothrombin, factors VII and IX) and factor V. No evidence was found of activation of the coagulation or fibrinolytic systems. The defects can be explained by deficient synthesis resulting from systemic hypoxia as well as from sluggishness of the local microcirculation caused by high blood viscosity. Vitamin K parenterally had no demonstrable effect. Replacement of these factors, possibly combined with measures to improve the microcirculation, therefore, appears to be the appropriate treatment.     

Haemostatic defects in cyanotic congenital heart disease.

An investigation of defects of the haemostatic mechanism in 41 children with cyanotic congenital heart disease concluded that such abnormalities were common and normally involved factors synthesised in the liver, that is the vitamin K dependent factors (rothrombin, factors VII and IX) and factor V. No evidence was found of activation of the coagulation or fibrinolytic systems. The defects can be explained by deficient synthesis resulting from systemic hypoxia as well as from sluggishness of the local microcirculation caused by high blood viscosity. Vitamin K parenterally had no demonstrable effect. Replacement of these factors, possibly combined with measures to improve the microcirculation, therefore, appears to be the appropriate treatment.     

Contraception in patients with congenital heart defects

The number of women with congenital cardiac disease, who mature into adulthood is increasing. Unfortunately, there are no prospective data published about the relative risk of different forms of contraception for these patients. Most women with congenital cardiac disease can safely use oral contraceptives, especially low-estrogen combination or progestin-only preparations, with the exception of those, who are at particular risk because of thromboembolic complications (especially in cyanosis, pulmonary hypertension, Eisenmenger reaction, rhythm disturbances), fluid retention (especially in reduced ventricular function and congestive heart failure), arterial hypertension (important in coarctation), infectious complications (endocarditis) or hyperlipidemia. Oral contraceptives should be avoided in patients at increased risk for thromboembolic events. Intrauterine devices are very effective, have no metabolic side effects and merely carry a small risk of endocarditis. Newer devices containing progesterone only may put the patients at a still smaller risk. Contraceptive subdermal implants (e.g. levonorgestrel) are used with good results in the United States for patients with contraindications to estrogen-containing oral contraceptives and may well become more widely accepted in patients in Germany in the coming years. Barrier methods can be used, but have a higher failure rate, which may be unacceptable in patients at risk (e.g. Eisenmenger's). Especially in Eisenmenger's, permanent sterilisation should be advised.