Non-sustained ventricular tachycardia in hypertrophic cardiomyopathy: an independent marker of sudden death risk in young patients

OBJECTIVES: The aim of this study was to examine the characteristics of non-sustained ventricular tachycardia (NSVT) episodes during Holter monitoring and to determine their relationship to age and prognosis. BACKGROUND: It has been suggested that NSVT is only of prognostic importance in patients with hypertrophic cardiomyopathy (HCM) when repetitive, prolonged, or associated with symptoms. METHODS: We studied 531 patients with HCM (323 male, 39 +/- 15 years). All underwent ambulatory electrocardiogram monitoring (41 +/- 11 h). RESULTS: A total of 104 patients (19.6%) had NSVT. The proportion of patients with NSVT increased with age (p = 0.008). Maximum left ventricular wall thickness and left atrial size were greater in patients with NSVT. Mean follow-up was 70 +/- 40 months. Sixty-eight patients died, 32 from sudden cardiac death (SCD). Twenty-one patients received an implantable cardioverter defibrillator (ICD). There were four appropriate ICD discharges. In patients < or =30 years (but not >30), five-year freedom from sudden death was lower in those with NSVT (77.6% [95% confidence interval (CI): 59.8 to 95.4] vs. 94.1% [95% CI: 90.2 to 98.0]; p = 0.003). There was no relation between the duration, frequency, or rate of NSVT runs and prognosis at any age. The odds ratio of sudden death in patients < or =30 years of age with NSVT was 4.35 (95% CI: 1.54 to 12.28; p = 0.006) compared with 2.16 (95% CI: 0.82 to 5.69; p = 0.1) in patients >30 years of age. CONCLUSIONS: Non-sustained ventricular tachycardia is associated with a substantial increase in sudden death risk in young patients with HCM. A relation between the frequency, duration, and rate of NSVT episodes could not be demonstrated.     

Significance of supraventricular arrhythmias induced by electrophysiologic studies

The clinical history and the findings on Holter monitoring of767 patients (without evidence of ventricular pre-excitationon the ECG) were compared with the results of electrophysiologicalstudies to assess the significance of supraventricular arrhythmiasinduced by intracardiac study. The studies were undertaken todetermine the cause of syncope, conduction disturbances or tachycardia. In 570 patients (group 1) supraventricular arrhythmias werenot induced. On Holter monitoring, 36 (6%) had evidence of supraventriculartachycardias, including atrial flutter, atrial fibrillationand paroxysmal junctional tachycardia. In 86 patients (group 2) one atrial extrastimulus induced aparoxysmal junctional tachycardia; 79 (82%) of these patientshad had spontaneous supraventricular tachycardia (SVT). In 111 patients (group 3) another type of SVT was induced: (a) The movement of the catheter induced atrial flutter or fibrillationin nine patients, eight (89%) of whom had spontaneous SVT. (b) Atrial pacing at a rate less than 200 bpm induced atrialflutter or fibrillation in 14 patients of whom nine (64%) hadSVT. (c) Ventricular pacing induced SVT in 15 patients, of whom 14(64%) had SVT. (d) An atrial extrastimulus during sinus rhythm induced atrialechoes in 62 patients, 47 (76%) of whom had SVT. (e) The atrial extrastimulus during sinus rhythm induced atrialtachycardia in 11 patients, nine (82%) of whom had SVT.     

Results of programmed ventricular stimulation in primary dilated cardiomyopathy

Programmed ventricular stimulation (PVS) has been advocated as being capable of identifying patients with idiopathic non obstructive dilated cardiomyopathy (NOCM) and at high risk of sudden death. We have studied the results of that method in 56 patients aged from 29 to 69 years (mean 53 years) presenting with idiopathic NOCM. The patients were divided into two groups according to the presence or absence of ventricular tachycardia (VT). Group I (controls) comprised 23 patients without documented VT. Group II consisted of 33 patients with documented VT which was sustained in 5 cases. Finally, 7 patients from both groups experienced losses of consciousness. Ventricular stimulation was performed on 2 sites of the right ventricle, using 1 to 3 extrastimuli on 2 imposed cycles. It was repeated under isoprenaline on 25 occasions. PVS induced non sustained ventricular tachycardia (NSVT) in only 2 patients of group I; it reproduced the sustained ventricular tachycardia (SVT) observed in the 5 patients with spontaneous SVT. PVS was negative in 14 of the 28 patients with NSVT; it induced NSVT in 8/28 and SVT in 6/28 (including 4 with more than 280 beats/min). The isoprenaline test failed to induce SVT. 7 patients died suddenly: 3 presented with SVT and 4 had syncopes and NSVT; ventricular stimulation induced SVT in 3 of these 4 patients. It is concluded that induction of sustained VT is uncommon in NOCM, but a history of syncope should prompt a search for SVT. Patients with spontaneous symptomatic NSVT and inducible SVT must be considered at high risk of sudden death.     

The Clinical Significance of Nonsustained Ventricular Tachycardia in Patients with Sustained Ventricular Tachyarrhythmias

Background: Nonsustained ventricular tachycardia (NSVT) predicts mortality in several disorders but its significance in patients with sustained ventricular tachyarrhythmias is unknown. We analyzed the clinical features and outcome associated with NSVT (>; 3 beats at >; 100 beats/min) recorded on a 48-hour Holter in the absence of antiarrhythmic drugs. Methods: Patients enrolled in the ESVEM trial (n = 486) were grouped according to the duration of the longest recorded episode of NSVT, and in the second analysis, according to frequency of recorded episodes. Assessments were on an intention-to-treat basis. Results: Patients without NSVT were more likely to have ischemic heart disease and had significantly lower frequencies of single and paired premature ventricular complexes (PVCs). There were no significant differences with respect to age, sex, presenting arrhythmia, years since last myocardial infarction, functional class, or present ejection fraction. The cumulative probabilities of arrhythmia recurrence and all-cause mortality at 4 years in patients without NSVT (60%± 7% and 32%± 6%, respectively) were not significantly different than those of patients with NSVT (63%± 3% and 41%± 3%, respectively). Cox regression models indicated that ejection fraction and functional class were significant predictors of outcome, but variables based on the presence, duration, and frequency of recorded episodes of NSVT were not. Conclusions: NSVT is common in patients with spontaneous and inducible sustained ventricular tachyarrhythmias and at least 10 PVCs/hour (ESVEM enrollment criteria), but is not a significant predictor of arrhythmia recurrence, sudden death, or all-cause mortality in patients with these characteristics.     

Long-term outcome and prognostic determinants in children with hypertrophic cardiomyopathy

Objectives. We sought to determine clinical, angiographic, and echocardiographic predictors of survival in children with isolated hypertrophic cardiomyopathy (HCM) in a large pediatric centre.

Background. Sudden death is a catastrophic outcome of HCM in childhood but has been difficult to predict. Current therapies might provide for improved outcome if factors identifying high risk can be identified.

Methods. Records of 99 patients diagnosed with HCM from 1958 to 1997 at <18 yr were reviewed for clinical, angiographic (n = 62) and echocardiographic (n = 83) predictors of survival outcome. The effects of clinical characteristics on sudden death (including resuscitated sudden death) were individually tested in Cox’s proportionate hazard modeling.

Results. Seventy-one subjects were male. Median age at diagnosis was 5.0 yr with a medical follow-up interval of 4.8 yr. Thirty-seven of 97 patients had a family history of HCM. Ambulatory electrocardiograms (ECG) in 78 patients demonstrated supraventricular tachycardia in 16 and ventricular tachycardia in 21. Death or resuscitated sudden death occurred in 18 patients. Sudden death rate was 2.7%/yr after age 8 yr. Cox’s proportionate survival modeling revealed increased corrected QT interval (QTc) dispersion on ECG (relative risk [RR] 1.61 per 20 ms increment, p < 0.0003), ventricular tachycardia (VT) on ambulatory ECG (RR 3.75, p < 0.006) and myocardial bridging of the LAD coronary (RR 12.0, p < 0.003) to be associated with reduced time to death or resuscitated sudden death.

Conclusions. Detailed assessment of ECGs, ambulatory ECGs, and coronary angiography can assist in identifying which children with HCM are at risk for sudden death.     

肥厚型心肌病延迟增强磁共振成像与心律失常的相关性

目的 探讨肥厚型心肌病延迟增强磁共振成像(MRI)显示的心肌纤维化与心律失常的相关性.方法 对48例未经治疗的肥厚型心肌病患者进行了MRI心功能分析、钆喷替酸葡甲胺(Gd-DTPA)延迟增强MRI、常规心电图和24 b动态心电图检查.分别探讨延迟增强MRI与频发室性期前收缩(PVCS总数≥200个)、阵发性室上性心动过速(SVT)、非持续性室性心动速(NSVT)、房室传导阻滞(AVB)、室内传导阻滞(IVB)之间的关系.计算延迟强化心肌质量、延迟强化心肌质量百分比,并分析其与24 h内PVCS、SVT和NSVT总数,传导阻滞(PR间期、QRS时限)间的相关性.描述肥厚型心肌病延迟强化节段的分布和特征.结果 48例肥厚型心肌病患者中35例出现延迟强化.出现PVCS、SVT、NSVT、AVB、IVB等心律失常的肥厚型心肌病患者中,延迟增强阳性患者出现PVCS、SVT、NSVT的数目显著大于延迟增强阴性患者(P=0.001～0.03).延迟强化心肌质量百分比与QRS时限呈正相关(r=0.33,P＜0.001).结论 延迟增强MRI显示的心肌纤维化与心律失常相关,可能为存在(或潜在)并发心律失常的肥厚型心肌病患者提供更多评估病情和预后的信息.     

Ambulatory ventricular arrhythmias in patients with heart failure do not specifically predict an increased risk of sudden death. PROMISE (Prospective Randomized Milrinone Survival Evaluation) Investigators

BACKGROUND: Ventricular arrhythmias are a frequent finding in congestive heart failure (CHF) patients and a cause of concern for physicians caring for them. Previous studies have reached conflicting conclusions regarding the importance of ventricular arrhythmias as predictors of sudden death in patients with CHF. This study examined the independent predictive value of ventricular arrhythmias for sudden death and all-cause mortality in PROMISE (Prospective Randomized Milrinone Survival Evaluation). METHODS AND RESULTS: Ventricular arrhythmias were analyzed and quantified by use of prespecified criteria on baseline ambulatory ECGs from 1080 patients with New York Heart Association (NYHA) class III/IV symptoms and a left ventricular ejection fraction 相似文献   

Prognostic value of non-sustained ventricular tachycardia and the potential role of amiodarone treatment in hypertrophic cardiomyopathy: assessment in an unselected non-referral based patient population

Background—Amiodarone has been reported to reduce the likelihood of sudden death in patients with hypertrophic cardiomyopathy (HCM). However, data regarding the clinical course in HCM have traditionally come from selected referral populations biased toward assessment of high risk patients.
Aims—To evaluate antiarrhythmic treatment for sudden death in an HCM population not subject to tertiary referral bias, closely resembling the true disease state present in the community.
Methods—Cardiovascular mortality was assessed in relation to the occurrence of non-sustained ventricular tachycardia (NSVT) on 24 or 48 hour ambulatory Holter recording, a finding previously regarded as a marker for sudden death, particularly when the arrhythmia was frequent, repetitive or prolonged. 167 consecutive patients were analysed by multiple Holter ECG recordings (mean (SD) 157 (129) hours) and followed for a mean of 10 (5) years. Only patients with multiple repetitive NSVT were treated with amiodarone, and in relatively low doses (220 (44) mg/day).
Results—Nine HCM related deaths occurred: 8 were the consequence of congestive heart failure, but only 1 was sudden and unexpected. Three groups of patients were segregated based on their NSVT profile: group 1 (n = 39), multiple ( 2 runs) and repetitive bursts (on 2 Holters) of NSVT, or prolonged runs of ventricular tachycardia, included 4 deaths due to heart failure; group 2 (n = 38), isolated infrequent bursts of NSVT, included 1 sudden death; group 3 (n = 90), without NSVT, included 4 heart failure deaths. Kaplan-Meier survival analysis showed no significant differences in survival between the three groups throughout follow up.
Conclusions—In an unselected patient population with HCM, isolated, non-repetitive bursts of NSVT were not associated with adverse prognosis and so this arrhythmia does not appear to justify chronic antiarrhythmic treatment. Amiodarone, administered in relatively low doses, did not carry an independent and additive risk for cardiac mortality. Amiodarone may have contributed to the absence of sudden cardiac death in patients believed to be at higher risk because of multiple repetitive NSVT.

Keywords: hypertrophic cardiomyopathy; ventricular tachycardia; amiodarone     

Prevalence and significance of nonsustained ventricular tachycardia in patients with premature ventricular contractions and heart failure treated with vasodilator therapy

Objectives. This study sought to determine the prevalence and significance of nonsustained ventricular tachycardia (NSVT) in patients with premature ventricular contractions (PVCs) and heart failure treated with vasodilator therapy.Background. Heart failure patients with ventricular arrhythmia and NSVT have a significantly increased risk of premature cardiac death. Recently there has been the question of whether these arrhythmias are expressions of a severely compromised ventricle or are they independent risk factors. We, therefore, determined the prevalence and significance of NSVT in patients with PVCs and heart failure and on vasodilator therapy.Methods. Twenty-four hour ambulatory recordings were done at randomization, at 2 weeks, at months 1, 3, 6, 9 and 12 and then every 6 months in 674 patients with heart failure and on vasodilator therapy. The median period of follow-up was 45 months (range 0 to 54).Results. Nonsustained ventricular tachycardia was present in 80% of all patients. Patients without (group 1) and with (group 2) NSVT were balanced for variables: age, etiology of heart disease, New York Heart Association (NYHA) functional class, use of amiodarone and diuretics and left ventricular diameter by echocardiogram. However, group 1 patients had significantly less beta-adrenergic blocking agent use and higher ejection fraction (EF) (p < 0.002 and p < 0.001, respectively). Survival analysis for all deaths showed a greater risk of death among group 2 patients (p = 0.01). Similarly, sudden death was increased in group 2 patients (p = 0.02, risk ratio 1.8). After adjusting for the above variables, only EF (p = 0.001) and NYHA class (p = 0.01) were shown to be independent predictors of survival. Nonsustained ventricular tachycardia showed a trend (p = 0.07) as an independent predictor for all-cause mortality but not for sudden death. Only EF was an independent predictor for sudden death.Conclusions. Nonsustained ventricular tachycardia is frequently seen in patients with heart failure and may be associated with worsened survival by univariate analysis. However, after adjusting other variables, especially for EF, NSVT was not an independent predictor of all-cause mortality or sudden death. These results have serious implications in that suppression of these arrhythmias may not improve survival.     

Impact of physical deconditioning on ventricular tachyarrhythmias in trained athletes.

OBJECTIVES: The purpose of this research was to evaluate the impact of athletic training and, in particular, physical deconditioning, on frequent and/or complex ventricular tachyarrhythmias assessed by 24-h ambulatory (Holter) electrocardiogram (ECG). BACKGROUND: Sudden deaths in athletes are usually mediated by ventricular tachyarrhythmias. METHODS: Twenty-four hour ambulatory ECGs were recorded at peak training and after a deconditioning period of 19 +/- 6 weeks (range, 12 to 24 weeks) in a population of 70 trained athletes selected on the basis of frequent and/or complex ventricular tachyarrhythmias (i.e., > or =2,000 premature ventricular depolarization [PVD] and/or > or =1 burst of non-sustained ventricular tachycardia [NSVT]/24 h). RESULTS: A significant decrease in the frequency and complexity of ventricular arrhythmias was evident after deconditioning: PVDs/24 h: 10,611 +/- 10,078 to 2,165 +/- 4,877 (80% reduction; p < 0.001) and NSVT/24 h: 6 +/- 22 to 0.5 +/- 2, (90% reduction; p = 0.04). In 50 of the 70 athletes (71%), ventricular arrhythmias decreased substantially after detraining (to <500 PVDs/24 h and no NSVT). Most of these athletes with reduced arrhythmias did not have structural cardiovascular abnormalities (37 of 50; 74%). Over the 8 +/- 4-year follow-up period, each of the 70 athletes survived without cardiac symptoms. CONCLUSIONS: Frequent and/or complex ventricular tachyarrhythmias in trained athletes (with and without cardiovascular abnormalities) are sensitive to brief periods of deconditioning. In athletes with heart disease, the resolution of such arrhythmias with detraining may represent a mechanism by which risk for sudden death is reduced. Conversely, in athletes without cardiovascular abnormalities, reduction in frequency of ventricular tachyarrhythmias and the absence of cardiac events in the follow-up support the benign clinical nature of these rhythm disturbances as another expression of athlete's heart.     

Effect of Corticosteroid Therapy on Ventricular Arrhythmias in Patients with Cardiac Sarcoidosis

Background: Ventricular arrhythmias are one of the main causes of sudden death in cardiac sarcoidosis (CS). Little is known about the efficacy of corticosteroid therapy for ventricular arrhythmias in CS. Methods: Thirty‐one CS patients presenting premature ventricular contractions (PVCs, ≥300/day) were investigated. Fourteen patients had nonsustained ventricular tachycardia (NSVT). All of patients were treated with corticosteroid, and the initial dosage is 30 mg/day of prednisone, which was tapered over a period of 6 months to a maintenance dosage of 10 mg/day. Twenty‐four hour Holter monitoring, signal averaged electrocardiography (SAECG), echocardiography, gallium‐67 scintigraphy, serum angiotensin converting enzyme (ACE) and plasma B‐type natriuretic peptide (BNP) concentrations were assessed before and after corticosteroid therapy. Results: As a whole, there were no significant differences in the number of PVCs and in the prevalence of NSVT before and after steroid therapy. However, the less advanced LV dysfunction patients (EF ≥ 35%, n = 17) showed significant reduction in the number of PVCs (from 1820 ± 2969 to 742 ± 1425, P = 0.048) and in the prevalence of NSVT (from 41 to 6%, p = 0.039). Late potentials on SAECG were abolished in 3 patients. The less advanced LV dysfunction group showed a significantly higher prevalence of gallium‐67 uptake compared with the advanced LV dysfunction group (EF < 35 %, n = 14). In the advanced LV dysfunction patients, there were no significant differences in these parameters. Conclusions: Corticosteroid therapy may be effective for ventricular arrhythmias in the early stage, but less effective in the late stage. Ann Noninvasive Electrocardiol 2011;16(2):140–147     

A study on clinical and electrophysiologic characteristics of ventricular tachycardia: comparison of differences on its sustenance

The purpose of this study was to clarify the difference of clinical and electrophysiologic characteristics between sustained ventricular tachycardia (SVT) and nonsustained ventricular tachycardia (NSVT). 40 patients consisting of 24 males and 16 females with an average age of 50.0 years (range from 19 to 83), who had shown ventricular tachycardia (VT) on electrocardiogram, were studied consecutively. The patients were divided into SVT group (19 cases) and NSVT group (21 cases). Ventricular stimulation was performed up to triple extrastimuli, and ventricular burst pacing was used when required. After VT was induced, R-R interval during VT was measured and an antiarrhythmic agent was given by bolus injection. Echocardiography was used for measurement of left ventricular ejection fraction (EF) and for evaluation of mitral valve prolapse (MVP). Palpitation and oppressive sensation were dominant in SVT (84.2%), while dizziness and syncope were prominent in NSVT (57.1%). Organic heart disease (OHD) was observed in only 42.1% of SVT, and in none of NSVT. MVP was observed in 6 patients of SVT and in 5 patients of NSVT. EF was significantly higher in NSVT (67.1%) than in SVT (56.9%) (p less than 0.02), while it was not significantly different in cases of NSVT and SVT where OHD was not present (64.4%). VT was induced and sustained in 17 out of 19 patients (89.5%) in SVT by ventricular stimulation. In NSVT, VT was induced in 6 of 21 patients (38.6%), but it was not sustained in any of them. The induction of VT in NSVT appeared to require more extrastimuli than in SVT. The R-R interval in SVT was longer than in NSVT (345.9 +/- 84.6 msec and 245.0 +/- 40.7 msec, p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)     

Clinical significance of T-wave alternans in hypertrophic cardiomyopathy.

The clinical significance of T-wave alternans (TWA) in hypertrophic cardiomyopathy (HCM) is unclear, so SV1+RV5 and QT dispersion on 12-lead electrocardiograms (ECG), the parameters of the left ventricle on echocardiography and the family history of HCM and sudden death were investigated in 53 patients with HCM who experienced TWA. The maximal numbers of successive ventricular ectopic beats (max VE) and nonsustained ventricular tachycardia (NSVT) were measured by Holter monitoring. In 13 patients, genetic abnormalities were examined. In 22 patients, the hypertrophy of myocytes, disarray and fibrosis were histopathologically examined using a scoring method. TWA was positive in 27 patients (TWA+ group), negative in 14 (TWA- group) and indeterminate in 12. The ECG and echocardiographic parameters, family history and genetic abnormalities did not significantly differ between the TWA+ and TWA- groups. Max VE, the percentage of patients with NSVT and disarray score in the TWA+ group were significantly higher than those in the TWA- group (3.6+/-3.6 vs 1.3+/-0.7, 37% vs 0%, 1.9+/-1.1 vs 0.7+/-0.5; p<0.05). TWA in HCM correlates with histopathological changes, especially disarray and ventricular tachyarrhythmia, and measuring it may be a noninvasive means of detecting high-risk patients with HCM.     

THE PREVALENCE OF ARRHYTHMIAS IN HYPERTROPHIC CARDIOMYOPATHY: ROLE OF AMBULATORY MONITORING AND SIGNAL-AVERAGED ELECTROCARDIOGRAPHY

Abstract Hypertrophic cardiomyopathy (HCM) is associated with a high incidence of supraventricular and ventricular arrhythmias. The presence of ventricular tachycardia (VT) in patients with HCM has been associated with a high risk of sudden death. Forty-seven patients with HCM (31 male, 16 female, mean age 47 years) underwent continuous 24-hour ambulatory electrocardiographic (ECG) monitoring. High grade ventricular arrhythmias (modified Lown class 3, 4a, 4b) were found in 20 patients (43%) with VT in 11 (24%). In each case the arrhythmia was asymptomatic. Supraventricular arrhythmias were detected in 16 patients (34%). Signal-averaged electrocardiography in 27 patients showed late potentials in three of 11 patients with repetitive ventricular arrhythmias and was negative in 15 of 16 patients without these arrhythmias. In conclusion, asymptomatic high grade ventricular and supraventricular arrhythmias are common in HCM and are readily detected with continuous electrocardiographic monitoring. Sinal-averaged ECG has low sensitivit for the detection of subclinical VT in patients with HCM. (Aust NZ J Med 1986; 16: 666–670.)     

Nonsustained ventricular tachycardia as a predictor for sudden death in patients with idiopathic dilated cardiomyopathy. The role of amiodarone treatment.

BACKGROUND: Sudden death frequently occurs in patients with idiopathic dilated cardiomyopathy. Ventricular arrhythmias are encountered in almost all cases. The prognostic significance of life-threatening arrhythmias such as successfully resuscitated ventricular fibrillation and sustained ventricular tachycardia is well known, while it is controversial for ventricular arrhythmias of a lower degree. Amiodarone has been used widely in these patients but its value in preventing sudden death is still uncertain. The aim of this study was to evaluate the prognostic significance of runs of nonsustained ventricular tachycardia (NSVT) as a hallmark for sudden death and the efficacy of amiodarone in preventing sudden death and reducing overall mortality in a large series of patients with dilated cardiomyopathy. METHODS: Over the period between 1983 and 1994, a series of 151 consecutive patients with idiopathic dilated cardiomyopathy underwent ambulatory electrocardiographic monitoring for a mean period of 191 hours/patient. Seventy-nine patients (56 male, mean age 50.7 +/- 13.1 years) (group A) had ventricular arrhythmias of Lown class < or = 4A, while 72 (53 male, mean age 48.6 +/- 12.8 years) (group B) had one or more NSVT runs. The two groups were well matched in terms of clinical features. Mean follow-up period was 86.8 +/- 38.7 and 74.7 +/- 39.5 months, respectively. In group A no antiarrhythmic drug was administered, while in group B 54/72 patients were treated with amiodarone (mean dosage 300 mg/day) for a mean period of 69.7 +/- 37.8 months (group B1). The remaining 18 patients received class I antiarrhythmic drugs, mexiletine (12) and propaphenone (6) for a mean period of 46.1 +/- 29.4 months, because amiodarone was contraindicated (3) or serious side-effects occurred during amiodarone treatment (15), which was discontinued after a mean period of 3.8 +/- 3.1 months (group B2). RESULTS: The cumulative survival probability in the whole population was 86.6% at two years and 65.6% at five years. The rate of sudden death was 6.0% at two years and 18.3% at five years. No statistically significant difference was observed in terms of all-cause mortality or sudden death in the three groups (A, B1, B2). In group B1, amiodarone determined the disappearance of NSVT at Holter monitoring in 50% of patients (27), with no significant difference in the rate of sudden death between the two subgroups. CONCLUSIONS: In unselected patients with idiopathic dilated cardiomyopathy, cardiovascular mortality does not differ between those with NSVT on chronic amiodarone treatment and those without NSVT who have not undergone antiarrhythmic therapy. There was a trend towards a higher overall and sudden mortality rate in patients with NSVT treated with other antiarrhythmic drugs vs patients with NSVT treated with amiodarone, but due to the small size of the first group no significant difference could be calculated. Assuming NSVT as a potential prognostic marker for sudden death, amiodarone treatment may have exerted a beneficial effect in these patients, but this statement is only a presumption due to the limitations of our study. The disappearance of NSVT during amiodarone treatment is not predictive of a reduced rate in sudden death, so that the potential effect of the drug does not appear to be related to the suppression of NSVT at Holter monitoring.     

Prognostic value of ventricular tachycardia induced by stimulation in patients without documented tachycardia

In order to determine the cause of syncopes or disorders of conduction, 584 programmed stimulations using 2 ventricular extrastimuli delivered during an imposed rhythm were performed, between 1981 and 1985, in patients without ventricular tachycardia (VT) proven by Holter recordings. Eighty-seven non-sustained VT (NSVT) (15%), 8 ventricular fibrillations (VF) (1%), 16 ventricular flutters (VF1) (3%) and 23 sustained VT (SVT) (4%) were induced. To appraise the significance of these responses the patients were followed up for a mean period of 2 +/- 1 years. Among the NSVT patients the first 47 were followed up until 1984 and the others, less numerous, until 1985. Patients who responded to stimulation with NSVT had (4.4%) or did not have an underlying cardiopathy; their mean left ventricular ejection fraction (LVEF) was 53.5 +/- 17% (n = 10); 17% died of heart disease, but the disease was related to VT in only one case; 36% of these patients had cardiac symptoms, but only one presented with episodes of NSVT. Patients who responded with VF had a normal (50%) or abnormal heart; their mean LVEF was 52 +/- 19%; one died of heart failure, the others were asymptomatic. All but one of the patients who responded with VF1 had an underlying cardiopathy and a mean LVEF of 38 +/- 19%; 3 died, 2 of heart failure and 1 of sudden death; 13 were asymptomatic. All patients who responded with SVT had an underlying cardiopathy and a mean LVEF of 37 +/- 13%; 7 (30%) died, including 2 sudden deaths; 2 had episodes of VT and 12 were asymptomatic. In summary, an underlying cardiopathy was present in one-half of the patients who responded with NSVT or VF and in all patients who responded with VF1 or SVT. The risk of VT was low (5%) in patients who responded with NSVT, VF or VF1 and was higher (17%) in those who responded with SVT.     

H?ufigkeit, Diagnostik und Therapie von Herzrhythmusst?rungen in der Schwangerschaft

Atrial premature beats are frequently diagnosed during pregnancy (PR), supraventricular tachycardia (SVT) less frequently. For acute therapy, electrical DC-cardioversion with 50–100 J is indicated in all unstable patients (pts). In stable SVT, the initial therapy includes vagal maneuvers to terminate breakthrough tachycardias. For short-term management, when vagal maneuvers fail, intravenous adenosine is the drug of first choice and may safely terminate the arrhythmia. Ventricular premature beats are also frequently present during PR and benign in most pts, while life-threatening ventricular tachyarrhythmias (sustained ventricular tachycardia (VT), ventricular flutter (VFlut), ventricular fibrillation (VF)) are observed less frequently. Electrical DC cardioversion is necessary in all pts with a hemodynamically unstable situation and life-threatening ventricular tachyarrhythmias; in hemodynamically stable pts, initial therapy with ajmaline, procainamide or lidocaine is indicated. In pts with syncopal VT, VF, VFlut or aborted sudden death, an implantable cardioverter-defibrillator is indicated. In pts with symptomatic bradycardia, a pacemaker can be implanted using echocardiography at any stage of PR.     

Longitudinal left ventricular strain in hypertrophic cardiomyopathy: correlation with nonsustained ventricular tachycardia

Aims: Stratifying risk of sudden death is a major issue in the management of hypertrophic cardiomyopathy (HCM). Existing risk factors have low positive predictive value and new parameters are needed. Determination of myocardial deformation (strain) by 2D Speckle tracking is a new methodology for determining LV regional function and could correlate with myocite disarray and fibrosis. The aim of this study was to assess the relationship between strain analysis and nonsustained ventricular tachycardia (NSVT) in patients with HCM. Methods: Thirty‐two consecutive patients with HCM (mean age 55, 17–78) were studied. All underwent standard echocardiographic and two‐dimensional strain examination. Twenty‐four‐hour Holter monitoring was performed and echocardiographic parameters were correlated with NSVT. Results: Nine patients (28%) had one or more episodes of NSVT. Patients with NSVT had a higher value of maximal LV thickness (23.6 mm vs. 19.4 mm, P = 0.027). There were no significant associations between NSVT on Holter monitoring and LV outflow gradient left atrial diameter, E/Em or left ventricle ejection fraction. Patients with HCM and NSVT had significant reductions in mid septal, apical‐septal, apical‐lateral strain, and in mean longitudinal strain. Midseptal strain >–10.5% had a sensitivity of 89% and a specificity of 74% (area under the curve, 0.787; P < 0.0013) for predicting NSVT independently of age or maximum wall thickness. Conclusion: Lower end‐systolic peak longitudinal strain obtained by 2D speckle tracking was a predictor of NSVT in HCM patients. This parameter could become a useful tool in stratifying SCD risk in this population. (Echocardiography 2011;28:709‐714)     

Early ECG Abnormalities Associated with Transcatheter Closure of Atrial Septal Defects Using the Amplatzer® Septal Occluder

Conduction abnormalities and arrhythmias may occur in patients following secundum atrial septal defect (ASD) closure using the Amplatzer® septal occluder (ASO). Therefore, the aim of this study was to prospectively perform ambulatory ECG monitoring to assess the electrocardiographic effects of transcatheter closure (TCC) of ASD using the ASO device.From 5/97 to 3/99, 41 patients with secundum ASD, underwent TCC using the ASO device at a median age of 9.2[emsp4 ]y. (0.5–87[emsp4 ]y.) and median weight of 34[emsp4 ]kg (5.6–88[emsp4 ]kg.). Ambulatory Holter monitoring was performed pre- and immediately post TCC. Holter analysis included heart rate (HR), ECG intervals, supraventricular ectopy (SVE), ventricular ectopy (VE), and AV block.No change in baseline rhythm was noted in 37 patients (90%). Changes in AV conduction occurred in 3 patients (7%), including intermittent second degree AV block type II, and complete AV dissociation post closure. SVE was noted in 26 patients (63%) post closure, ranging from 5–2207 supraventricular premature beats (SVPB), including 9 patients (23%) with non-sustained supraventricular tachycardia (SVT), 3 of whom had short runs of SVT prior to closure. A significant increase in post-closure number of SVPB per hour (p=0.047) was noted. No significant difference was noted in PR interval, ventricular premature beats per hour, or QRS duration. Conclusions: Based on ambulatory ECG analysis, TCC of ASD with the ASO device is associated with an acute increase in SVE and a small risk of AV conduction abnormalities, including complete heart block. Long term follow-up studies will be necessary to determine late arrhythmia prevalence and relative frequency compared with standard surgical ASD repair.