Types Of Structural Heart Disease Research Articles

Procedure feasibility and mid-term follow-up of left bundle branch area pacing using stylet-driven pacing leads with a fixed-curve delivery sheath in patients with structural heart disease

Abstract Background Recently, left bundle branch area pacing (LBBAP) has been performed using style-driven extendable screw-in leads with newly introduced pre-shaped delivery sheath in South Korea. There are limited data on the feasibility of LBBAP in patients with structural heart disease (SHD). Purpose To evaluate LBBAP procedure feasibility and mid-term follow-up data of LBBAP lead profile in pateints with SHD Methods Patients, in which LBBAP was attempted, were consecutively enrolled at the Seoul National University Hospital from January 2021 to December 2022. LBBAP was performed with stylet-driven lead (Solia S60, Biotronik) delivered through a delivery sheath (Selectra 3D, Biotronik). Procedure feasibility, LBBAP success rate, and mid-term LBBAP lead threshold were evaluated in patients with or without various type of SHD. Results A total of 121 patients were enrolled (mean age 73.5±12.2 years). Atrioventricular block was the most common indication (n=94, 77.7%), followed by atrial fibrillation with slow ventricular rate (n=12, 9.9%), sick sinus syndrome (n=10, 8.3%), and heart failure indicated cardiac resynchronized therapy (n=5, 4.1%). LBBAP success rate was 89.3% of total study population, deep septal pacing was achieved in 4.1%, and right ventricle apex pacing were performed in 6.6%. Fifty-one patients (42.1%) were accompanied by SHD (Figure). Patients with SHD had significantly lower left ventricular ejection fraction than those without SHD (54±13% vs. 62±5%, p<0.001). Baseline QRS duration was longer in patients with SHD (107±26 ms vs. 135±35 ms, p=0.005). Although LBBAP success rate was significantly lower in patients with SHD than those without in total study population (80.4% vs. 95.7%, p=0.007), LBBAP success rate was not differ between two groups after excluding first 30 cases (98.1% in patients without SHD vs. 97.4% in patients with SHD, p=0.811) (Figure). Among patients with successful LBBAP, total procedure time was longer in pateints with SHD, but there was no significant difference of fluoroscopic time, bipolar V sensing, V pacing threshold, and V impedance between the two groups (Figure). Pateints with SHD had longer left ventricular activation time (LVAT) (80±13ms vs. 72±9 msec, p=0.003), but there was no statistically significant difference in the final QRS duration between the two groups (104±14 ms in patients without SHD vs. 111±14 msec in patients with SHD, p=0.955). During mean 19±6 months follow-up, there was no significant V threshold increase in both groups. Conclusion LBBAP using stylet-driven pacing leads in patients with SHD is feasible and safe as in patients without structural heart disease, even by an early experienced operator with LBBAP procedure.

Sex differences in ventricular arrhythmia: epidemiology, pathophysiology and catheter ablation.

Evidence on sex differences in the pathophysiology and interventional treatment of ventricular arrhythmia in ischemic (ICM) or non-ischemic cardiomyopathies (NICM) is limited. However, women have different etiologies and types of structural heart disease due to sex differences in genetics, proteomics and sex hormones. These differences may influence ventricular electrophysiological parameters and may require different treatment strategies. Considering that women were consistently under-represented in all randomized-controlled trials on VT ablation, the applicability of the study results to female patients is not known. In this article, we review the current knowledge and gaps in evidence about sex differences in the epidemiology, pathophysiology and catheter ablation in patients with ventricular arrhythmias.

Evaluation of the frequency and types of structural heart disease in fetuses of pregnant women according to risk groups by fetal echocardiography

Aim: The aim of this study is to evaluate the frequency of congenital heart diseases (CHD) encountered in low-risk and high-risk pregnant women by fetal echocardiographic (FE) examination. Material and Method: The records of 855 pregnant women with a gestational week greater than 16 who applied to the pediatric cardiology outpatient clinic of our hospital between July 2019- October 2021 and underwent FE were analyzed retrospectively. Results: CHD was detected in 109 (12.7%) of 855 pregnant women who were referred to our center and underwent FE examination. Frequency of CHD was given according to risk groups. The rate of CHD in patients in the high-risk group was 15.2%, while it was 9% in patients in the low-risk group (p=0.008). Significant CHD was 6.2% in the high-risk group versus 2.7% in the low-risk group (p=0.016). The most common structural cardiac anomaly in FE examination was ventricular septal defect (38.5% in 42 fetuses), and the second most common cardiac anomaly was atriyoventricular septal defect (18.3% in 20 fetuses). Conclusion: In our study, it was found a higher rate of CHD in pregnant women in the high-risk group than in the low-risk group and especially significant CHD was detected more common in pregnant women in the high-risk group.

A QRS axis–based algorithm to identify the origin of scar-related ventricular tachycardia in the 17-segment American Heart Association model

Previously proposed algorithms to predict the ventricular tachycardia (VT) exit site have been based on diverse left ventricular models, but none of them identify the precise region of origin in the electroanatomic map. Moreover, no electrocardiographic (ECG) algorithm has been tested to predict the region of origin of scar-related VTs in patients with nonischemic cardiomyopathy. The purpose of this study was to validate a simple ECG algorithm to identify the segment of origin (SgO) of VT relative to the 17-segment American Heart Association model in patients with structural heart disease (SHD). The study included 108 consecutive patients with documented VT and SHD [77 (71%) with coronary artery disease]. A novel frontal plane axis-based ECG algorithm (highest positive or negative QRS voltage) together with the polarity in leads V3 and V4 was used to predict the SgO of VT. The actual SgO of VT was obtained from the analysis of the electroanatomic map during the procedure. Conventional VT mapping techniques were used to identify the VT exit. In total, 149 12-lead ECGs of successfully ablated VT were analyzed. The ECG-suggested SgO matched with the actual SgO in 122 of the 149 VTs (82%). In 21 of the 27 mismatched ECG-suggested SgOs (77.8%), the actual SgO was adjacent to the segment suggested by the ECG. There were no differences in the accuracy of the algorithm based on the SgO or the type of SHD. This novel QRS axis-based algorithm accurately identifies the SgO of VT in the 17-segment American Heart Association model in patients with SHD.

Abstract 13751: Categorizing the Burden of Arrhythmia in Adults With Congenital Heart Disease

Introduction: Advances in surgical and medical therapies have increased the life expectancy for patients with congenital heart disease. Arrhythmias in these patients are common and multi-factorial, often due to a disruption of the hearts’ intrinsic electrical system and degenerative remodeling, secondary to varying pressure and volume loads. The aim of this study is to better characterize the association between type of structural heart disease (SHD) and clinically significant arrhythmias. Methods: We identified all adults with diagnosed congenital heart disease seen at a large tertiary care referral center between 2000 and 2014. Patients were categorized based on gender, SHD, and type of arrhythmia. We used the American Thoracic Society guidelines to group SHD into discrete categories and grouped arrhythmias as tachyarrhythmias (atrial/ventricular) and bradyarrhythmias. Results: We identified 1355 individuals with at least one congenital structural heart defect and at least one arrhythmia. Of those, the most common structural abnormality was left-sided outflow tract obstruction and the least common was congenitally corrected transposition of the great arteries. The most common category of arrhythmia identified was atrial arrhythmia and the least common was sinoatrial node dysfunction (Figure). The most common association between SHD and arrhythmia was atrial arrhythmia in patients with left-sided outflow tract obstruction. Conclusions: This study is one of the largest single-center reports linking specific structural heart defects to type of rhythm disturbance. These data may help providers better anticipate future arrhythmia development based on a patient’s underlying structural defect and offer prognostic information to patients and families. Future studies to more closely evaluate the relationship between arrhythmia patterns and specific risk factors within each category of SHD are needed.

Tricuspid valve interventions in 2015.

When the incidence of tricuspid regurgitation is taken into account, along with its impact on functional status and long-term survival, tricuspid regurgitation is currently undertreated. Today, though transcatheter therapy of aortic, mitral- and pulmonic valve disease is well established, interventional treatment of tricuspid valve disease is still in its early stages. Currently, various promising devices are in different stages of development, but it is still too early to clarify which interventional approach in the future might result in functional and clinical success. Similarly, it is yet unclear which type of patient subpopulation will benefit from this type of treatment. Seen in the current context of the overall evolution in the adoption of catheter-based treatments for other types of structural heart disease, the need for and interest in effective interventional treatments for tricuspid regurgitation is growing.

Long-term Outcomes of Ventricular Tachycardia Ablation in Different Types of Structural Heart Disease.

Ventricular tachycardia (VT) often occurs in the setting of structural heart disease and can affect patients with ischaemic or nonischaemic cardiomyopathies. Implantable cardioverter-defibrillators (ICDs) provide mortality benefit and are therefore indicated for secondary prevention in patients with sustained VT, but they do not reduce arrhythmia burden. ICD shocks are associated with increased morbidity and mortality, and antiarrhythmic medications are often used to prevent recurrent episodes. Catheter ablation is an effective treatment option for patients with VT in the setting of structural heart disease and, when successful, can reduce the number of ICD shocks. However, whether VT ablation results in a mortality benefit remains unclear. We aim to review the long-term outcomes in patients with different types of structural heart disease treated with VT ablation.

Risk Factors, Clinical Pattern and Outcome of Stroke in a Referral Hospital, Northwest Ethiopia

Stroke is one of the commonest causes of morbidity and mortality among non-communicable diseases. Its occurrence has been significantly increasing in Sub Saharan Africa in the last couple of decades. Mortality has been shown to be higher in this area compared to developed countries. Yet, there is a big information gap about stroke in Ethiopia. This study aimed at describing the clinical pattern, risk factors and outcome of adult stroke patients admitted to university of Gondar hospital. Retrospective chart record analysis of adult patients with stroke who had Computerized tomography(CT) scan of the brain admitted to University of Gondar hospital medical wards from June 2010 to May 2013 was done. Relevant data including sociodemographics, risk factors, type of stroke and outcome were collected using a data extraction form. Data was entered and analyzed using Epi info7. Results: A total of 98 patients with a median age of 68 years (IQR: 60-76) and F:M ratio of 1.13:1 were analyzed. Ischemic stroke accounted for 69.4% of the cases. The median ages of patients with hemorrhagic and ischemic stroke were 60 and 70 years respectively (P=0.0027). Hypertension (55.9%), any type of structural heart disease (44.6%) and atrial fibrillation (28.7%) were the most commonly identified risk factors. Atrial fibrillation was more prevalent in ischemic stroke patients (34.3%) compared to hemorrhagic stroke (14.8%) (P= 0.049). In hospital mortality rate was 13% with median duration of hospital stay before death of 6 days. Respiratory failure secondary to aspiration pneumonia and increased intracranial pressure were the most common immediate causes of death. Conclusion: Even though ischemic stroke was the most common stroke subtype, the proportion of hemorrhagic stroke was higher compared to studies from the developed world. Appropriate screening and treatment of hypertension, structural heart disease and atrial fibrillation should be give due attention as they are the most commonly identified risk factors. Most deaths occurred early after admission due to stroke related acute complications with respiratory failure; as such an emergency stroke care unit capable of managing these complications can partially decrease the death rate.

Assessment of the right ventricle in pregnant women with and without structural heart disease

We would like to thank the authors for their valuable comments on ourmanuscript and certainlywelcome the suggestion formore interest in right ventricular function in pregnant women with structural heart disease [1,2]. While evaluation of its functioning seems evident in lesions with right sided involvement, it is probably essential in all types of structural heart disease as it becomes more and more evident that left sided dysfunction often involves or induces right ventricular dysfunction [3]. While the latter is often less apparent, it is indeed not less important. The problem remains that there are no data on normal right ventricular function during uncomplicated pregnancy for comparison. It thenbecomesdifficult todiscernbetweenphysiological changes related to pregnancy and pathological changes due to the structural defect. The neglection of right ventricular assessment can largely be attributed to the difficulties in obtaining straightforward representative measurements with ultrasound. Evenmore than for its left counterpart, most parameters only crudely reflect aspects of right ventricular function. Interpretation is then highly dependent of underlying structural abnormalities and changing loading conditions [4]. Assessment of volume and ejection fraction with 2-D ultrasound is severely hampered by the anterior position and complex shape of the right ventricle [4]. The gold standard remains cardiacmagnetic resonance (CMR). 3-D is promising but still remains challenging in patients with structural heart defects [5,6]. In assessing other parameters of right ventricular systolic function, one has to bear in mind that the interplay between intrinsic myocardial performance and loading conditions is evenmore complex as for the left ventricle. Therefore, development of load independent markers of right ventricular function, especially with changing conditions during pregnancy, is essential [3]. As suggested, several parameters like tricuspidal annular plane systolic excursion (TAPSE), Tissue Doppler velocities as well as strain, strain rate and myocardial acceleration during myocardial contraction (IVA), the latter being less load dependent, are promising [4,7]. Still most of them also have their intrinsic limitations and normal values for pregnancy are lacking for comparison. We performed CMR of the right ventricle in a subgroup of our population and will soon submit our data. Unfortunately we did not asses right ventricular function by ultrasound in a systematic way [2]. We think that more research on normal values of both ventricles with the latest ultrasound techniques is primordial in healthy pregnant women and agree that parameters of right ventricular function should then be included in studies of pregnantwomenwith heart disease. Only then will we be able to truly asses the influence of pregnancy on global heart function in these women.

Noninvasive Parameters for Evaluation of Activation Delay in Arrhythmogenic Cardiomyopathy

Prolonged electric activation delay between 2 sites in the heart is due to slow conduction, lengthening of conduction pathways, or both. In the presence of unidirectional block and triggers, enhanced delay promotes reentrant circuits as substrate of arrhythmogenesis in various supraventricular and ventricular arrhythmias. This mechanism is well-known in the chronic stage of myocardial infarction and other types of structural heart disease, including arrhythmogenic cardiomyopathy (AC).1–3 Article see p 475 AC can be defined as, ultimately, a structural heart disease, with signs of heart failure preceded in the early stages by electrophysiological alteration that result in electrocardiographic abnormalities and ventricular arrhythmias. AC includes primarily right ventricular, primarily left ventricular, or biventricular abnormalities.4,5 Arrhythmogenic right ventricular dysplasia/cardiomyopathy is well-known nomenclature for the right-sided variant. However, although histopathological and functional predominance of right ventricular abnormalities are frequently found, the left ventricle is affected in most patients as well. Moreover, at the molecular level, both ventricles are affected by altered expression and distribution of intercalated disk proteins.6–8 Because of these considerations, AC has recently become the favored terminology of this group of frequently difficult-to-distinguish disorders. AC is considered a genetic disorder primarily associated with gene mutations encoding desmosomal proteins, although nondesmosomal genes are also involved in a minority, but substantial number of cases.9–11 Accumulating evidence suggests that gene mutation-related changes or distribution of desmosomal proteins give rise to altered expression and distribution of other intercalated disk proteins, including gap junction and ion channel proteins, resulting in mechanical and electric uncoupling …

A Prospective Study on the Risk-Stratification for Patients With Non-Sustained Ventricular Tachycardia Using a Novel Algorithm

The therapeutic strategy for non-sustained ventricular tachycardia (NSVT), considered as a risk-stratifier for sudden cardiac death (SCD), still remains undetermined. In the present study 222 of 4,079 patients (5.4%) hospitalized with NSVT during 2002 to 2004 were prospectively evaluated using an algorithm for risk-stratification according to each type of structural heart disease. The algorithm comprises the left ventricular ejection fraction, signal-averaged electrocardiography, programmed ventricular stimulation and the family history of SCD. Of the 222 patients, 151 (68.0%) were successfully risk-stratified and 32 patients consequently received an implantable cardioverter defibrillator (ICD) (21.2%; algorithm-ICD group). The remaining 119 patients without an ICD (algorithm-observation group) were observed. During 27.7+/-11.4 months of follow-up, the patients in the algorithm-ICD group had a significantly higher prevalence of tachyarrhythmic events than did those in the algorithm-observation group (9/32 vs 1/119; p<0.05). In the algorithm-ICD group, 2, 1 and 6 patients experienced an SCD, aborted SCD and appropriate ICD intervention, respectively, while there was only 1 SCD in the algorithm-observation group. The proposed algorithm for risk-stratification of patients with NSVT may be feasible for appropriate selection of high-risk patients and candidates for prophylactic ICD implantation.

Atrial Fibrillation in a Patient with Left Ventricular Hypertrophy after Induction of General Anesthesia: A case report

Atrial fibrillation is the common sustained cardiac arrhythmia. Risk factors for atrial fibrillation include hypertension, diabetes, valvular and other types of structural heart disease. Echocardiographic variables including left atrial enlargement, increased left ventricular wall thickness, and reduced left ventricular fractional shortening are predictive of risk for atrial fibrillation. We experienced a case of newly developed hemodynamically unstable atrial fibrillation after induction of general anesthesia. The patient had hypertension, diabetes, increased left ventricular wall thickness, and reduced left ventricular fractional shortening. Atrial fibrillation was treated with electrical cardioversion. Atrial fibrillation disappeared and hemodynamic parameters became stable.

B-Type Natriuretic Peptide Testing for Structural Heart Disease Screening: A General Population-Based Study

Background Several types of structural heart disease are important precursors for congestive heart failure or cardioembolic stroke. We have previously demonstrated that plasma B-type natriuretic peptide (BNP) measurement is useful for detection of structural heart disease in a multiphasic health screening setting. To extend our hypothesis to the general population, the utility of BNP testing for identifying structural heart disease was assessed in a general population and in subgroups divided by sex, age, and presence/absence of risk factors. Methods and Results This cross-sectional cohort study measured plasma BNP concentrations in 993 randomly selected community-dwelling adults (mean age 58 years). All subjects underwent plasma BNP measurement and transthoracic echocardiography. Using prejudged criteria, 41 subjects were diagnosed to have some form of structural heart disease (mild left ventricular systolic dysfunction in 11, valvular heart disease in 9, hypertensive heart disease in 3, hypertrophic cardiomyopathy in 2, ischemic heart disease in 2, lone atrial fibrillation in 14). The utility of BNP testing was evaluated by receiver operating characteristic (ROC) analysis and by cost analysis for detection of 1 case within each subgroup of the cohort. Overall, the sensitivity and specificity of BNP testing for identification of structural heart disease were 61% and 92%, respectively. The area under the ROC curve was 0.77 (95% CI; 0.74–0.79). When sex-specific ROC analyses were performed, sensitivity and specificity were 61% and 91% in men, and 50% and 95% in women, respectively. Although the performance of BNP testing on the basis of these figures might be suboptimal, efficacy was improved in subgroups with a high prevalence of heart disease (>8%) such as the cohort aged ≥65 years (men, area under ROC curve = 0.88; cost <US$1400: women, area under ROC curve = 0.83; cost <US$3000) as well as the cohort having cardiovascular risk factors such as hypertension or diabetes (men, area under ROC curve = 0.85; cost <US$1700: women, area under ROC curve = 0.83; cost <US$3100). Conclusion The present results suggest that BNP testing for structural heart disease screening in community-based populations is useful for cohorts with a high prevalence of heart disease. However, its efficacy is reduced in cohorts with a low prevalence rate.

Comparison of Positive Cases for B-type Natriuretic Peptide and ECG Testing for Identification of Precursor Forms of Heart Failure in an Elderly Population

Plasma B-type natriuretic peptide (BNP) levels have been reported to be elevated in various types of cardiac disorders and in precursors of CHF. To elucidate the potential ability of BNP testing to identify individuals with structural cardiac disease (ie, hypertensive heart disease, coronary heart disease, valvular heart disease) among community-dwelling elderly persons, cases which were positive on BNP testing were compared to those positive on ECG testing. In the initial phase, we performed plasma BNP measurements and ECG in 856 participants (age > or = 65 years) selected from a general population. From within this group, subjects with an abnormal ECG (n = 125) were selected according to the Minnesota code. Subjects with elevated BNP were selected independently on the basis of plasma levels (n = 112). In the next phase, subjects in both groups were invited to complete Rose's angina questionnaire and to undergo physical examination and transthoracic echocardiography. In this subject group (positive in ECG testing and/or BNP testing), the two tests had comparable sensitivity (65% versus 59%: NS) and specificity (40% versus 41%: NS) for identifying hypertensive heart disease (n = 17). For coronary heart disease (n = 12), the two tests had also comparable sensitivity (58% versus 42%: NS) and specificity (39% versus 41%: NS). However, for selection of valvular heart disease (n = 7), BNP testing had higher sensitivity than ECG testing (100% versus 14%; P < 0.01) with comparable specificity (43% versus 40%: NS). Several types of structural heart disease, in particular valvular heart disease, could be identified exclusively by BNP testing, suggesting that BNP measurement can make a significant contribution to screening for CHF precursors when used in combination with ECG in elderly populations.

Tachycardia-Related Cardiomyopathy in Patients with Atrial Fibrillation

During atrial fibrillation, an uncontrolled ventricular response may result in extensive changes in ventricular function and structure referred to as tachycardia-related cardiomyopathy [1–3]. These consequenses of tachyarrhythmia are crucial since it may be reversible with tachycardia rate or rhythm control. A detailed review of the present knowledge regarding tachycardia-related cardiomyopathy and therapy for rate control was published by the authors in 1998 [4]. Our present understanding of tachycardiainduced cardiomyopathy relies mainly on experiments in animal models. Sustained rapid atrial or ventricular pacing can produce severe biventricular systolic and diastolic dysfunction in animals. The heart failure is characterized by elevated ventricular filling pressures, impairment of left and right ventricular systolic function, increased left and right end-systolic and end-diastolic volumes, reduction of cardiac output, and elevation of systemic vascular resistance. The mechanisms responsible for the hemodynamic and structural changes associated with pacing-induced cardiomyopathy have not been fully elucidated. However, a potential role for abnormal calcium channel activity is likely. Myocyte action potentials show reduced membrane resting potential and upstroke velocity as well as prolonged duration at 90% repolarization. Action potential prolongation could be due to an absolute reduction in L-type calcium current flow into the myocyte, caused by reduced open probability of the channel. Once heart failure has developed in the clinical setting, additional adrenergic activation may initiate an important vicious cycle with further enhancement of ventricular response leading to further reduction of cardiac output and amplification of heart failure. Control of fast ventricular response is immediately beneficial in tachycardia-related cardiomyopathy. In animal models after termination of pacing, mean arterial pressures, cardiac output and systemic vascular resistance approach control levels within 48 hours. Left ventricular ejection fraction normalizes completely after 1–2 weeks. In clinical studies, a marked improvement in left ventricular function generally starts after 1 month of cessation of the tachycardia and may continue for another 6–8 months. Therefore, treatment of tachycardia should be the primary goal in those patients. Methods of rate control include drug therapy, complete AV junction ablation and AV node modification. In patients with structural heart disease, more aggressive therapeutic options like complete AV node ablation can be appropriate since in these patients the progression to congestive heart failure may be fast. Impairment of left ventricular function due to atrial fibrillation has been reported in all age groups, in structurally normal hearts, and in various types of structural heart disease. However, the prevalence of tachycardia-related cardiomyopathy is still matter of speculation and commonly considered to be very low. In a recently published substudy of the Ablate and Pace Trial, the prevalence of tachycardiarelated cardiomyopathy was determined in patients who were referred for complete AV junction ablation and consecutive pacemaker implantation for therapy of atrial fibrillation [5]. The authors examined patients who had reduced ejection fraction before atrioventricular ablation and determined how many of them had tachycardia-related cardiomyopathy, as evidenced by a normalization of their systolic function 3 and 12 months after ventricular rate control by AV junction ablation and right ventricular pacing. In this study, sixty-three out of a total of 161 patients had systolic dysfunction. Forty-eight of these patients had at least one follow-up echocardiographic study, and thus, were subject to study. It was found that 16 of the 48 patients had a marked improvement in the ejection fraction to a value higher than 45% following ventricular rate control by AV junction ablation. And although patients eligible for AV ablation are at high risk for tachycardia-related cardiomyopathy because many of them have not been able to obtain heart

Symptomatic Ventricular Tachycardia.

The approach to patients with symptomatic ventricular tachycardia (VT) depends on the presence and type of structural heart disease. In patients with underlying heart disease and ventricular fibrillation or sustained symptomatic VT with hemodynamic compromise, the implantable cardioverter-defibrillator (ICD) is superior to antiarrhythmic drugs for the improvement of overall survival. These patients should receive an ICD unless contraindications are present. For patients with sustained VT and a structurally normal heart (idiopathic VT), radiofrequency catheter ablation is a reasonable option. If patients are symptomatic, nonsustained VT should be treated with beta-adrenergic blocking agents or antiarrhythmic drugs, which should be selected on the basis of the underlying cardiovascular substrate. In patients with coronary artery disease, depressed left ventricular function, and nonsustained VT, we recommend the use of programmed electrical stimulation for additional risk stratification. If a sustained ventricular arrhythmia is induced, an ICD should be implanted.

A comparison of 50-J versus 100-J shocks for direct-current cardioversion of atrial flutter

Background Direct-current cardioversion remains the gold standard for restoration of sinus rhythm in patients with atrial flutter. Although an initial energy of 50 J is recommended, the optimal energy settings have not been evaluated in a large series of contemporary patients. Methods We compared the outcome of cardioversion with 50 J versus 100 J in 330 consecutive patients with atrial flutter. Initial energy was based on attending physician preference. One hundred sixty patients received 50 J and 170 patients received 100 J. Results Patients in both groups did not differ significantly in age, sex, weight, body mass index, duration of the arrhythmia, postoperative status, presence and type of structural heart disease, or use of antiarrhythmic drugs. Patients in the 100-J group had more first shock conversion (85% vs 70%; P = .001), fewer total shocks (1.2 ± 0.5 vs 1.4 ± 0.7; P = .001), and less induction of atrial fibrillation (2% vs 11%; P = .002). There were no significant differences in overall restoration of sinus rhythm, cumulative energy delivered, anesthetic dose, and procedure room time. On multivariate analysis, delivery of 100 J was the strongest predictor of first shock success (odds ratio 2.6, 95% confidence interval 2.13 to 3.16; P < .001). Conclusion An initial energy of 100 J is more efficient for restoration of sinus rhythm in patients with atrial flutter. (Am Heart J 1999;137:439-42.)

Unusual Forms of Ventricular Tachycardia.

An overview of four unusual types of ventricular tachycardia is presented: arrhythmogenic right ventricular dysplasia, bundle branch reentry, and idiopathic left and right ventricular tachycardias. In most patients with these tachycardias, severe structural heart disease is absent. The prognosis of patients is dependent on the clinical manifestations produced by the arrhythmia and the presence and type of structural heart disease. We describe their clinical, electrocardiographic, and electrophysiologic features. Based on the most common clinical courses and tachycardia mechanisms, current management options are discussed.