Incidence, predictive factors, and prognostic significance of supraventricular tachyarrhythmias in congestive heart failure

BACKGROUND

The incidence, predictive factors, morbidity, and mortality associated with the development of supraventricular tachyarrhythmias (SVTs) in patients with congestive heart failure (CHF) are poorly defined.

METHODS

In the Digitalis Investigation Group trial, patients with CHF who were in sinus rhythm were randomly assigned to digoxin (n = 3,889) or placebo (n = 3,899) and followed up for a mean of 37 months. Baseline factors that predicted the occurrence of SVT and the effects of SVT on total mortality, stroke, and hospitalization for worsening CHF were determined.

RESULTS

Eight hundred sixty-six patients (11.1%) had SVT during the study period. Older age (odds ratio [OR], 1.029 for each year increase in age; p = 0.0001), male sex (OR, 1.270; p = 0.0075), increasing duration of CHF (OR, 1.003 for each month increase in duration of CHF; p = 0.0021), and a cardiothoracic ratio of > 0.50 (OR, 1.403; p = 0.0001) predicted an increased risk of experiencing SVT. Left ventricular ejection fraction, New York Heart Association functional class, and treatment with digoxin vs placebo were not related to the occurrence of SVT. After adjustment for other risk factors, development of SVT predicted a greater risk of subsequent total mortality (risk ratio [RR] = 2.451; p = 0.0001), stroke (RR = 2.352; p = 0.0001), and hospitalization for worsening CHF (RR = 3. 004; p = 0.0001).

CONCLUSION

In CHF patients in sinus rhythm, older age, male sex, longer duration of CHF, and increased cardiothoracic ratio predict an increased risk for experiencing SVT. Development of SVT is a strong independent predictor of mortality, stroke, and hospitalization for CHF in this population. Prevention of SVT may prolong survival and reduce morbidity in CHF patients.

[Pre and Postoperative evaluation of the incidence of arrhythmia in patients undergoing corrective intervention for Ebstein anomaly]

BACKGROUND

Patients with Ebstein's anomaly frequently have troublesome cardiac arrhythmias. In particular, this malformation is the most common congenital defect associated with the Wolff-Parkinson-White syndrome. The aim of this study was to investigate the postoperative evolution of arrhythmias without the aid of any surgical techniques for arrhythmia.

METHODS

Between 1980 and 1999, 48 patients (22 males, 26 females), with a preoperatively documented arrhythmia, underwent an operation for the correction of Ebstein's anomaly at the Hôpital Broussais. Of these, 24 had paroxysmal supraventricular tachycardia, 12 had atrial fibrillation or flutter, 8 had Wolff-Parkinson-White syndrome, 1 had non-sustained ventricular tachycardia, and the remaining 3 patients had atrioventricular block.

RESULTS

The operative mortality was 8% (4/48). After operation 46% (20/44) of the patients regained permanent sinus rhythm (20/44 vs 2/48, p < 0.01), supraventricular tachyarrhythmia occurred in 16% of the patients (7/44), 8 patients (18%) had atrial fibrillation, and ventricular preexcitation syndrome was present in 3 patients (7%). The incidence of pacemaker implantation for complete heart block was 11% (5/44). Follow-up was achieved in 95% of patients (40/44) who survived the operation and the perioperative period. The mean follow-up was 63 +/- 54 months (range 4-226 months). During this time there were 6 additional deaths. Eight patients continued to have symptomatic arrhythmias (2 had paroxysmal supraventricular tachycardia, 6 had atrial fibrillation), but 55% of patients (20/36) reported no symptoms of arrhythmia (20/36 vs 2/48, p < 0.01).

CONCLUSIONS

Surgical repair improves the quality of life of these patients by reducing the incidence of arrhythmias, in fact less than one sixth of patients continued to have postoperative symptomatic arrhythmias. This can be explained by the interruption of accessory pathways that seem to be a major cause of arrhythmia in Ebstein's anomaly.

Residual atrial fibrillation and clinical consequences following postoperative supraventricular arrhythmias

AIMS

This retrospective study investigated whether the supraventricular arrhythmias (SVA) observed during cardiac surgery are limited to or persist beyond the postoperative period, their clinical consequences and whether they are influenced by preoperative and postoperative factors.

METHODS

A total of 375 patients undergoing elective bypass graft surgery over a 15-month period by three surgeons were included. All patients had their preoperative medications continued to the day of surgery and prophylactic anti-arrhythmic medications were not used in any of the cases. Standard anaesthetic techniques were used. Rhythm disturbances were diagnosed by ECG. The arrhythmias were treated medically or by cardioversion. All patients were followed up for 6 months.

RESULTS

Postoperative SVA occurred in 25% of patients. The commonest arrhythmia was atrial fibrillation (89.4%), followed by atrial flutter (6.4%) and supraventricular tachycardia (4.2%). In 89. 8% of the cases, the arrhythmias occurred within the first four postoperative days with a maximum incidence on the second day (27. 7%). Atrial fibrillation was still present in 50% of patients at hospital discharge and in 39% at 6 months follow up. Patients with arrhythmias had a prolonged hospital stay (7.7+/-2.6 vs. 6.0+/-2.6 days; P<0.05). There was no hospital mortality in the study and the incidence of postoperative stroke was equal in the sinus rhythm and arrhythmia patients (1.1%). SVA were more frequent when cardioplegia was used to protect the heart (32%) than with intermittent ischaemia (9%; P<0.001). At 6 months follow up, the patients receiving cardioplegia also had a higher prevalence of atrial fibrillation than those operated with intermittent ischaemia (41% vs. 22%; P<0. 05). The incidence of SVA and persistence of atrial fibrillation was unrelated to other preoperative and intraoperative factors.

CONCLUSION

Postoperative supraventricular arrhythmias have a long-lasting effect on cardiac rhythm: patients with SVA have a high probability of remaining in atrial fibrillation at hospital discharge and 6 months after surgery. The occurrence of atrial fibrillation seems to be influenced by the type of myocardial protection used but this does not appear to exert harmful effects.

Long-term prospective study on the natural history of Wolff-Parkinson-White syndrome detected during a heart screening program at school

In the period 1985 to 1993, a total of 802 school-aged children (284 first-graders and 518 seventh-graders) were referred to our hospital for further evaluation of electrocardiographic abnormalities. Among them, 57 (male 24 and female 33) children were confirmed as having Wolff-Parkinson-White (WPW) syndrome based on the findings of 12-lead surface electrocardiograms (ECG). According to Lindsay's criteria, the locations of the accessory pathways were as follows: Left-lateral in 10 (18%), left-posterior in 2 (4%), right-free-wall in 28 (49%), anterior-septum in 13 (23%) and posterior-septum in 3 (5%). One 12-y-old girl had multiple accessory pathways. Six patients had associated diseases: Ebstein's anomaly in 4, epilepsy in 1 and mental retardation with scoliosis in 1. Follow-up periods ranged from 2.0 to 13.0 y (mean +/- SD: 8.0 +/- 3.3 y) for 23 first-graders with WPW syndrome, and from 2.0 to 13.0y (mean +/- SD: 7.3 +/- 4.2y) for 34 seventh-graders, respectively. Initially, 5 children had at least one episode of supraventricular tachycardia (SVT) by history and 6 children developed SVT during the follow-up. One girl with multiple accessory pathways and recurrent SVT required long-term drug therapy.

CONCLUSIONS

The outcome of children with WPW syndrome detected by a heart screening program at school was favorable. Our 8 y follow-up of 57 children with WPW syndrome will serve as additional information concerning the indication of radio-frequency catheter ablation therapy for WPW syndrome in children.

[Incidence, clinical characteristics and prognostic significance of supraventricular tachyarrhythmias in acute myocardial infarction]

OBJECTIVES

The study of incidence and prognostic significance of supraventricular tachyarrhythmias in patients with acute myocardial infarction.

PATIENTS AND METHODS

Prospective study on 1,239 patients consecutively admitted because of a diagnosis of acute myocardial infarction. Clinical characteristics, indexes of myocardial infarction and complications were analysed.

RESULTS

Supraventricular tachyarrhythmias were observed in 116 (9.3%) cases: atrial fibrillation in 96 (7.7%); atrial tachycardia in 15 (1.2%); and atrial flutter in the remaining five cases (0.4%). Patients with supraventricular tachyarrhythmias were older, and presented higher heart rate, lower blood pressure, a higher number of affected leads in ECG, and higher Killip class. A higher creatine kinase peak and a lower left ventricular ejection fraction were associated with the presence of supraventricular tachyarrhythmias. Predictors of supraventricular tachyarrhythmias were: age, systolic blood pressure, number of affected leads in ECG, and congestive heart failure at admission. The following complications were found more frequently in patients with supraventricular tachyarrhythmias: bundle-branch block, complete A-V block, ventricular tachycardia, ventricular fibrillation; heart failure; stroke; and mortality, in-hospital 18.1% vs 11.1% (p < 0.05) and one-year, 38.7% vs 18.4% (p < 0.001). The logistic regression model showed that supraventricular tachyarrhythmias had no independent prognostic value on mortality.

CONCLUSIONS

The appearance of supraventricular tachyarrhythmias during the acute phase of myocardial infarction is a relatively frequent finding, often associated with older age and larger infarctions. Supraventricular tachyarrhythmias are accompanied by higher short and long-term mortalities, although there is no independent prognostic significance.

Recurrence risk of supraventricular tachycardia in pediatric patients

We analyzed risk of recurrence of supraventricular tachycardia (SVT) in 70 pediatric patients using both Kaplan-Meier survival analysis and logistic regression of likelihood of recurrence, each with covariates: (1) age at onset of SVT; (2) presence of Wolff-Parkinson-White syndrome (WPW), and (3) gender. Among 38 patients who had onset of SVT <1 year, only 11 had a recurrence, while among 32 older patients, 30 had a recurrence of SVT (p < 0.00001, Fisher's exact test). The survival analyses, stratified by age at onset <1 versus >1 year, were significantly different (p < 0.0001) as was stratification by presence of WPW (p < 0.01). Logistic regression analysis showed that the only significant predictor of recurrence was age at onset; the additional information provided by presence of WPW and gender did not significantly add to the prediction of recurrence. The odds ratio of recurrence for age at onset >1 versus <1 year was 34.6, with a 95% confidence interval of 6.98-172.

Arrhythmias and women

The incidence and risk factors for a variety of arrhythmias differ among men and women. Although symptomatic atrial reentrant tachycardias have a female predominance, the reverse is true for atrial fibrillation. Women have a lower incidence of sudden death. On the other hand, drug-induced torsades de pointes and symptomatic long QT syndrome have a female predominance. The incidence of arrhythmias seem to be increased during pregnancy. The mechanisms of these gender differences are unclear but may be related to hormonal effects and the shorter QT interval in men. Pharmacologic and nonpharmacologic therapy are equally efficacious in men and women.

Beta-adrenergic blockade accelerates conversion of postoperative supraventricular tachyarrhythmias

BACKGROUND

Postoperative supraventricular tachyarrhythmia is a common complication of surgery. Because chemical cardioversion is often ineffective, ventricular rate control remains a principal goal of therapy. The authors hypothesized that patients with supraventricular tachyarrhythmia after major noncardiac surgery who receive intravenous beta-adrenergic blockade for ventricular rate control would experience conversion to sinus rhythm at a rate that differs from those receiving intravenous calcium channel blockade.

METHODS

The rate of conversion to sinus rhythm at 2 and 12 h after treatment was examined in 64 cases of postoperative supraventricular tachyarrhythmia. After adenosine administration, patients who remained in supraventricular tachyarrhythmia were prospectively randomized to receive either intravenous diltiazem or intravenous esmolol for ventricular rate control (unblinded). Loading and infusion rates were adjusted to achieve equivalent degrees of ventricular rate control.

RESULTS

Patients were similar with regard to age and Apache III score. Most patients in both groups had atrial fibrillation (esmolol, 79%; diltiazem, 81%), and none experienced stable conversion with adenosine. Patients randomized to receive esmolol experienced a 59% rate of conversion to sinus rhythm within 2 h of treatment, compared with only 33% for patients randomized to receive diltiazem (intention to treat, P = 0.049; odds ratio, 2.9; 95% confidence interval, 1.046 to 7.8). After 12 h of therapy, the number of patients converting to sinus rhythm increased in both groups (esmolol, 85%; diltiazem, 62%), and the rates of conversion no longer differed significantly. Ventricular rates when supraventricular tachyarrhythmia began and after 2 and 12 h of rate control therapy were similar in the two treatment groups. The in-hospital mortality rate and length of stay in the intensive care unit were not significantly influenced by treatment group.

CONCLUSIONS

Among adenosine-resistant patients in the intensive care unit with atrial fibrillation after noncardiac surgery, intravenous esmolol produced a more rapid (2-h) conversion to sinus rhythm than did intravenous diltiazem.

Predictors of early- and late-onset supraventricular tachyarrhythmias after Fontan operation

BACKGROUND

The objectives of our study were to determine the frequency of supraventricular tachyarrhythmias (SVTAs) among modifications of the Fontan operation and identify risk factors for developing SVTA.

METHODS AND RESULTS

The population consisted of all patients who had any modification of the Fontan operation at the Mayo Clinic between 1985 and 1993. Clinically significant SVTAs were those requiring initiation or change of antiarrhythmic treatment, and they were divided into early SVTAs (<30 days after the operation) and late SVTAs (>/=30 days after the operation). Clinical histories were reviewed, and health status questionnaires were sent. Four hundred ninety-nine patients had various modifications of the Fontan operation. Frequency of early SVTA was 15%. Risk factors identified by multivariate analysis for early SVTA were AV valve regurgitation, abnormal AV valve, and preoperative SVTA. Frequency of late SVTA was 6% by 1 year, 12% by 3 years, and 17% by 5 years. Risk factors for late SVTA were age at operation (<3 or >/=10 years) and systemic AV valve replacement. By univariate and multivariate analysis, the type of Fontan operation was not a significant risk factor for late SVTA when all 6 modifications were considered. However, when we analyzed the frequency of late SVTA for the 2 recently used modifications, we found a lower frequency of late SVTA in patients with atriopulmonary connection with lateral tunnel compared with those with total cavopulmonary connection.

CONCLUSIONS

Postoperative SVTA continues to be a significant problem. Risk factors for SVTA are AV valve regurgitation, abnormal AV valve, preoperative SVTA, and age at operation. Frequency of SVTA does not appear to be related to type of Fontan procedure except for slightly lower frequency in patients with atriopulmonary connection with lateral tunnel compared with those with total cavopulmonary connection.

Paroxysmal supraventricular tachycardia in the general population

OBJECTIVES

We sought to determine the epidemiology and clinical significance of paroxysmal supraventricular tachycardia (PSVT) in the general population.

BACKGROUND

Current knowledge of PSVT has been derived primarily from otherwise healthy patients referred to specialized centers.

METHODS

We used the resources of the Marshfield Epidemiologic Study Area, a region covering practically all medical care received by its 50,000 residents. A review of 1,763 records identified prevalent cases as of July 1, 1991 and all new cases of PSVT diagnosed from that day until June 30, 1993. A mean follow-up period of 2 years was completed in all incident patients. Patients without other cardiovascular disease were labeled as having "lone PSVT."

RESULTS

The prevalence was 2.25/1,000 persons and the incidence was 35/100,000 person-years (95% confidence interval, 23 to 47/100,000). Other cardiovascular disease was present in 90% of males and 48% of females (p = 0.0495). Compared with patients with other cardiovascular disease, those with lone PSVT were younger (mean 37 vs. 69 years, p = 0.0002), had a faster PSVT heart rate (mean 186 vs. 155 beats/min, p = 0.0006) and were more likely to have their condition first documented in the emergency room (69% vs. 30%, p = 0.0377). The onset of symptoms occurred during the childbearing years in 58% of females with lone PSVT versus 9% of females with other cardiovascular disease (p = 0.0272).

CONCLUSIONS

There are approximately 89,000 new cases/year and 570,000 persons with PSVT in the United States. In the general population, there are two distinct subsets of patients with PSVT: those with other cardiovascular disease and those with lone PSVT. Our data suggest etiologic heterogeneity in the pathogenesis of PSVT and the need for more population-based research on this common condition.

Prevention of supraventricular tachyarrhythmias after open heart operation by low-dose sotalol: a prospective, double-blind, randomized, placebo-controlled study

BACKGROUND

The aim of this prospective, double-blind, placebo-controlled trial was to assess the preventive effect and safety of low-dose sotalol after heart operation.

METHODS

Two hundred fifty-five consecutive patients referred for elective coronary artery bypass grafting (n = 220) or aortic valve operation (n = 35) were randomized to receive either 80 mg of sotalol twice daily (n = 126) or matching placebo (n = 129) for 3 months, with the first dose given 2 hours before operation.

RESULTS

There were no significant baseline differences between the groups. Overall, supraventricular tachyarrhythmias occurred in 36% of patients (82% atrial fibrillation). Hospital stay was 11.6 +/- 5 days in patients with supraventricular arrhythmias, versus 9.5 +/- 2.4 days in patients without it (p < 0.0001). Low-dose sotalol reduced the rate of supraventricular arrhythmias from 46% (placebo) to 26% (sotalol; p = 0.0012), or by 43%. On the fourth postoperative day, heart rate was lower in the sotalol group (74 +/- 12 beats/min versus 85 +/- 15 beats/min; p < 0.0001) but the QT interval corrected for the heart rate was not prolonged (sotalol group, 0.44 +/- 0.03 second; placebo group, 0.43 +/- 0.03 second; p = not significant). Study medication had to be discontinued because of side effects in 5.6% of sotalol and 3.9% of placebo patients (p = not significant), with one possible proarrhythmic event occurring in a patient receiving sotalol.

CONCLUSIONS

Because more than 90% of supraventricular arrhythmic episodes occurred within 9 days after operation and 70% of all possibly sotalol related side effects occurred after day 9, the findings in this study imply that prophylactic treatment with sotalol may be limited to the first 9 postoperative days.

Multicenter comparative study of the efficacy and safety of sotalol in the prophylactic treatment of patients with paroxysmal supraventricular tachyarrhythmias

We performed a randomized, double-blind, placebo-controled, parallel-group comparison study of the efficacy and safety of sotalol in the prophylaxis of paroxysmal supraventricular tachyarrhythmias (PSVTs) (including paroxysmal atrial fibrillation and paroxysmal reentrant SVTs). The frequency of PSVT episodes while not receiving drug therapy was monitored during a baseline phase, the length of which depended on the frequency of PSVT events. In the double-blind phase, the duration of which depended on the baseline frequency of episodes of PSVT, patients received placebo, sotalol 80 mg twice daily, or sotalol 160 mg twice daily. PSVT events were documented by electrocardiogram and diary. The time to recurrence of PSVT was significantly less compared with placebo when receiving sotalol 80 mg (p = 0.018) and sotalol 160 mg (p = 0.0009). On subanalysis, sotalol was shown to be effective in the prophylaxis of both paroxysmal atrial fibrillation and paroxysmal reentrant arrhythmias. Sotalol was well tolerated, with no deaths, proarrhythmia, or cardiac failure. Because of adverse effects, drug therapy was discontinued in six patients.

Do echocardiographic changes explain the age-associated increase in exercise-induced supraventricular arrhythmias?

Although exercise-induced supraventricular arrhythmias (EISVA) increase with advancing age, it is unclear whether age-associated changes in cardiac structure or function play a major role in this increase. To address this question, we examined the relationship between M-mode echocardiographic variables and EISVA occurring during maximal treadmill exercise in 366 healthy volunteers aged 20 to 90 years from the Baltimore Longitudinal Study of Aging. Simple (i.e., isolated) EISVA were detected in 69 subjects (19%), and complex EISVA (i.e., comprising > 10% of beats in any minute or occurring in runs) in another 29 subjects (8%). Univariate predictors of any EISVA, whether simple or complex, were older age (p < 0.0001), male gender (p < 0.05), greater left atrial size (p < 0.01), left ventricular mass index (p < 0.0001), interventricular septal thickness (p < 0.001), isovolumic relaxation time (p < 0.01), atrial filling fraction (p < 0.01), reduced mitral E-F closure slope (p < 0.001), peak E velocity (p < 0.02), and peak E/A ratio (p < 0.0001). Lesser exercise duration (p < 0.01), lower maximal heart rate (p < 0.0001), and higher peak systolic and diastolic blood pressures (p < 0.001) were also associated with EISVA. However, by multiple logistic regression analysis, age (p < 0.0001) was the only independent predictor of any EISVA. Univariate predictors of complex EISVA were greater age (p < 0.0001), and atrial filling fraction (p < 0.001), diastolic blood pressure (p < 0.05), lesser mitral E-F slope (p < 0.004), exercise duration (p < 0.005) and maximal heart rate (p < 0.01). However, only age (p < 0.0001) independently predicted complex EISVA. Thus, in healthy volunteers undergoing maximal treadmill exercise. EISVA are associated with greater left ventricular wall thickness, reduced early diastolic performance, diminished exercise capacity and elevated exercise blood pressure. However, none of these variables are independent predictors of EISVA over and above the powerful effect of age.

Interatrial septal aneurysms and atrial arrhythmias in infants

Studies have suggested that interatrial septal aneurysms (IASAs) may be the initiating mechanism of supraventricular tachycardia (SVT) in newborns and infants. A retrospective study was performed to determine the incidence of IASAs in 30 infants with atrial arrhythmias (SVT, atrial flutter, or frequent premature atrial contractions) and their possible relation to the mechanism of atrial arrhythmias. An IASA was defined as dilation of the septum > 5 mm beyond the plane of the atrial septum and associated with redundant tissue and abnormal mobility. The study patients were compared with age and sex-matched control subjects. Four (13%) of the 30 study patients and 2 (7%) of 30 control subjects had an IASA (difference not significant). In contrast to previous reports, this study demonstrates that there is not a significant relation between the presence of IASAs and the onset and recurrence of atrial arrhythmias.

Comparison of the ages of tachycardia onset in patients with atrioventricular nodal reentrant tachycardia and accessory pathway-mediated tachycardia

Atrioventricular nodal reentrant tachycardia and accessory pathway-mediated tachycardia may have different ages of tachycardia onset. Symptom onset data were obtained in 519 patients (atrioventricular nodal reentrant tachycardia, 231, accessory pathway-mediated tachycardia, 288). The mean age of the patients at the time of evaluation was 47 +/- 17 years (atrioventricular nodal reentrant tachycardia) and 37 +/- 15 years (accessory pathway-mediated tachycardia). The mean age of symptom onset was 32 +/- 18 years for atrioventricular nodal reentrant tachycardia and 23 +/- 14 years for accessory pathway-mediated tachycardia. A significantly greater proportion of patients with atrioventricular nodal reentrant tachycardia had the initial onset of symptoms after the age of 20 years (atrioventricular nodal reentrant tachycardia, 67% vs accessory pathway-mediated tachycardia, 41%, p < 0.001). In summary, there is a different mean age of symptom onset for patients with atrioventricular nodal reentrant tachycardia and accessory pathway-mediated tachycardia.

[Postoperative early complication of primary lung cancer]

We analyzed postoperative early complications of primary lung cancer in 321 cases during 1982 to 1993 in our hospital, and assessed the prevention and the treatment against these complications. In order of frequency the complications are, paroxymal supraventricular tachcarida (10.6%), atelectasis due to sputum (6.9%), pulmonary fistula for more than seven days (4.7%), hoarseness of voice due to recurrent nerve palsy (4.0%), chylothorax (2.5%), gastrointestinal tract complications (2.2%), reoperation due to massive bleeding (1.2%), wound dehiscence (0.9%), bronchial fistula (0.6%), rupture of ascending aorta (0.3%) and myocardial infarction (0.3%). The two cases of bronchial fistula after pneumonectomy, and one of myocardial infarction after lobectomy through the median approach died of early complications. The operative indication for primary lung cancer is extended to the patients with higher age and lower pulmonary function; so we should be careful for the pre and postoperative prevention and the rapid and appropriate treatment against these postoperative early complications.

Supraventricular tachycardia. Occasional nuisance or frequent threat?

Supraventricular tachycardias (SVTs) are common and are widely regarded as a nuisance. They are often repetitive and persistent, and cause more upset than is currently acknowledged although only rarely do they threaten life. Surprisingly, they are ill-defined. A modern approach to SVT requires an accurate diagnosis and a readiness to abandon obsolete therapies in favour of effective new strategies, whether pharmacological or ablative.

Postoperative complications after pneumonectomy for treatment of lung cancer: multivariate analysis

The charts of 62 patients with primary lung cancer who underwent a pneumonectomy at our department from 1979 through 1992 were reviewed for the evaluation of postoperative morbidity and mortality. The 30-day mortality was 3/62 or 4.8%. Postoperative complication occurred in 37 of 62 patients (60%). The most common complication was a supraventricular tachyarrythmia. A major complication, which was defined as one necessitating re-thoracotomy or one which caused death, occurred in 19 patients (31%). We analyzed 43 perioperative variables for their predictive value of postoperative morbidity and mortality. Univariate analysis indicated that an elevated serum LDH, low predicted forced vital capacity, low predicted forced expiratory volume in 1 sec (FEV1) were significantly associated with the occurrence of a major complication. A multivariate logistic regression model indicated that a high LDH level, a low predicted FEV1 and no extubation following surgery were associated independently with a postoperative major complication. Since only the complete removal of a tumor offers a chance for cure for the treatment of non-small cell lung cancer, it is sometimes necessary to perform a pneumonectomy for these high-risk patients. Patients identified as being at high risk of a major complication should be candidates for intensive preoperative evaluation and perioperative care.

Clinical and echocardiographic correlates of symptomatic tachydysrhythmias after noncardiac thoracic surgery

BACKGROUND

Supraventricular tachydysrhythmias (SVTs) following thoracic surgery occur with significant frequency and may be associated with increased morbidity. Prospective data on the etiology and importance of these dysrhythmias are sparse.

METHODS

In 100 patients undergoing pulmonary resection without history of atrial dysrhythmias or previous thoracic surgery, we examined the effects of predefined risk factors by history, pulmonary function, and echocardiography on the incidence of postoperative SVT. Serial echocardiograms were performed preoperatively, on postoperative day 1, and again between postoperative days 2 to 6 (median = 3) to evaluate cardiovascular function and to estimate right ventricular systolic pressure (RVSP) by the tricuspid regurgitation jet (TRJ) Doppler velocity method.

RESULTS

Symptomatic postoperative SVT occurred in 18 (18%) of the 100 patients studied at a median of 3 days after surgery and was disabling in 12 of 18 (67%). Digoxin loading was ineffective in controlling the ventricular response in 16 of 17 episodes. In the patients developing SVT, postoperative echocardiography revealed significant elevation of TRJ Doppler velocity (2.7 +/- 0.6 m/s vs 2.3 +/- 0.6 m/s, p < 0.05) but not right atrial or ventricular enlargement or right atrial pressure increase when compared with patients without SVT. Independent correlates of SVT determined in a stepwise logistic regression included intraoperative blood loss > or = 1 L (p = 0.0001) and a postoperative TRJ Doppler velocity > or = 2.7 m/s (p < 0.05). Patients who developed SVT had a higher rate of intensive care unit admission (p < 0.004), a longer hospital stay (p < 0.02), and higher 30-day mortality (p < 0.02).

CONCLUSIONS

These prospective data suggest that increased right heart pressure but not fluid overload or right heart enlargement predisposes to clinically significant SVT after pulmonary resection. SVT may be an important marker of poor cardiopulmonary reserve in patients who develop significant morbidity after thoracic surgery. Early interventions to reduce right heart pressure may decrease the incidence of postoperative SVT and potentially improve overall surgical outcomes.

Prevalence and prognostic significance of atrial arrhythmias after orthotopic cardiac transplantation

OBJECTIVES

We studied the duration and prognostic significance of atrial arrhythmias in the denervated transplanted heart, specifically the occurrence of atrial fibrillation in the absence of vagal modulation.

BACKGROUND

Substantial animal data indicate that vagally induced dispersion of atrial refractoriness plays a central role in the induction and maintenance of atrial fibrillation.

METHODS

We studied the occurrence of atrial arrhythmias in the denervated hearts of 88 consecutive orthotopic transplantations in 85 patients by means of continuous telemetry and all available electrocardiographic tracings.

RESULTS

Fifty percent of recipients (44 of 88) developed at least one atrial arrhythmia. Atrial fibrillation occurred 23 times (21 recipients), atrial flutter 39 times (26 recipients), ectopic atrial tachycardia 3 times (3 recipients) and supraventricular tachycardia 18 times (11 recipients). The number of atrial fibrillation and atrial flutter episodes did not differ (23 vs. 39, p = 0.072), but the mean duration of atrial flutter was longer than that of atrial fibrillation (37.0 +/- 10 vs. 6.6 +/- 3.6 h, p = 0.014). Atrial fibrillation was associated with an increased risk of subsequent death (10 of 21 recipients with vs. 15 of 67 without atrial fibrillation, risk ratio 3.15 +/- 0.18, p = 0.005 by Cox proportional hazards model). All 5 recipients who developed "late" atrial fibrillation (> 2 weeks after transplantation) died versus 5 of 16 who developed atrial fibrillation within the first 2 weeks (p = 0.007). Causes of death included rejection (three recipients), allograft failure (two recipients), infection (three recipients) and multiorgan failure (two recipients). Atrial fibrillation was not associated with age, gender, ischemic time, reason for transplantation, echocardiographic variables, invasive hemodynamic variables or biopsy grade. Mean time from atrial arrhythmia to echocardiography was 2.7 +/- 3.3 days; that to biopsy was 4.8 +/- 6.3 days. Atrial flutter was not associated with subsequent death. Only 7 (15.9%) of 44 recipients demonstrated moderate or severe allograft rejection at the time of the arrhythmia.

CONCLUSIONS

Atrial arrhythmias occur frequently in the denervated transplanted heart, often in the absence of significant rejection. Late atrial fibrillation may be associated with an increased all-cause mortality.

Prevalence and prognostic significance of exercise-induced supraventricular tachycardia in apparently healthy volunteers

The prevalence, characteristics, and prognostic significance of supraventricular tachycardia (SVT) occurring during maximal treadmill exercise testing were examined in 843 male and 540 female asymptomatic volunteers aged 20 to 94 years from the Baltimore Longitudinal Study of Aging who underwent exercise testing a mean of 2.3 times between 1977 and 1991. Exercise-induced SVT occurred during at least 1 test in 51 men (6.0%) and 34 women (6.3%), p = NS for gender. The 85 subjects with exercise-induced SVT were significantly older than the 1,298 free from this arrhythmia (66.0 +/- 13.5 vs 49.7 +/- 18.0 years, respectively, p < 0.001). The prevalence of SVT increased with age in men (p < 0.001) but not in women. Ninety-eight percent of the 141 discrete episodes of exercise-induced SVT were paroxysmal SVT, with heart rates varying from 105 to 290 beats/min (mean 186.3 +/- 43.3); only 16% were > 10 beats in duration and only 4% of subjects were symptomatic. Nearly half (44%) of SVT episodes occurred at peak effort. Coronary risk factors, echocardiographic left atrial size (3.3 +/- 6.7 vs 3.3 +/- 0.6 cm), and the prevalence of exercise-induced ischemic ST-segment depression (11% vs 13%) were similar in 85 subjects with SVT and 170 control subjects matched for age and sex.(ABSTRACT TRUNCATED AT 250 WORDS)

Atrial arrhythmias in adults after repair of tetralogy of Fallot. Correlations with clinical, exercise, and echocardiographic findings

BACKGROUND

The long-term success of intracardiac repair of tetralogy of Fallot is hampered by the occurrence of arrhythmias. Numerous studies have stressed the potential role of ventricular arrhythmias. However, the importance of other arrhythmias in the morbidity of these patients appears to be underestimated. Furthermore, most follow-up studies have been limited to children or adolescents, whereas many patients have reached adulthood after earlier repair of tetralogy of Fallot. The aim of the present study was to determine the incidence of atrial fibrillation, atrial flutter, and other supraventricular arrhythmias in adult patients after intracardiac repair for tetralogy of Fallot and their correlation with surgical and clinical findings.

METHODS AND RESULTS

The study group consisted of 53 consecutive patients referred to the Thoraxcenter adult congenital heart disease clinic. They underwent repair at a mean age of 9.1 years (range, 0.7 to 55 years). The median age at the time of study was 23.2 years (range, 15 to 57 years; mean age, 26.6 years), and the mean duration of follow-up of 17.5 years (range, 1.4 to 32 years) after surgery. Records were reviewed extensively for evidence of arrhythmias. The follow-up study included routine 12-lead ECG, 24-hour continuous ambulatory monitoring, and echocardiography, and 46 patients underwent exercise testing. Sinus node dysfunction was recorded in 19 patients (36%), of whom 4 required a permanent pacemaker. Atrial fibrillation or flutter was found in 12 patients, and other supraventricular tachycardias were found in 6. The former were more frequently of older age at follow-up. Antiarrhythmic therapy and cardioversion were typically directed at control of atrial (and not ventricular) tachyarrhythmias. Ten patients (19%) showed nonsustained ventricular tachycardia; they were older at initial surgery and older at follow-up and had more intracardiac repairs and longer cardiopulmonary bypass times.

CONCLUSIONS

Despite an emphasis on ventricular ectopy in past series, the main sources of morbidity in adult patients after surgical correction of tetralogy of Fallot emanated from atrial arrhythmias, which were present in one third of the patients.

Importance of the time of onset of supraventricular tachyarrhythmias on prognosis of patients with acute myocardial infarction

It is known that left ventricular (LV) function, severity of coronary artery disease, and the presence of ventricular arrhythmias are major determinants of prognosis in patients surviving an acute myocardial infarction (AMI). However, little is known about the relationship between the time of onset of supraventricular tachyarrhythmias (SVTs) and mortality. Therefore, this study was carried out in a 48-months period on 131 patients with AMI who presented with SVT during hospitalization. Of these, 53 patients (40.5%) had arrhythmia within < 12 h of MI, while 78 patients (59.5%) had arrhythmia between 12 h and 4 days. The arrhythmias studied were atrial fibrillation, atrial flutter, and paroxysmal supraventricular tachycardia. The patients were similar for age, gender, coronary risk factors, creatine kinase-MB peak, cardioversion and LV function. Angiographic features for patients with the < 12-h onset of arrhythmia were: 86.7% of the patients had uniarterial lesions, 8.9% had biarterial lesions, and 4.4% had triarterial lesions. Patients with the 12-h-4-day onset had 16.1%, 53.2%, and 30.6% (p < or = 0.05) of the respective lesions. Inferior wall myocardial infarction was more frequent among patients with the earlier onset (60.4%), while patients with the later onset presented more anterior wall infarctions (50.0%). Only 11.3% of the patients with the earlier onset presented with severe in-hospital congestive heart failure (Killip classes III-IV), versus 62.8% of the patients with the later onset (p < or = 0.0001).(ABSTRACT TRUNCATED AT 250 WORDS)