Simple Ventricular Arrhythmias Research Articles

Arrhythmogenic cardiomyopathy in children according to “Padua criteria”: Single pediatric center experience

IntroductionThe aim of this study was to report clinical and arrhythmic features in a pediatric population affected by arrhythmogenic cardiomyopathy (ACM). Moreover, we assessed the concordance between the 2010 International Task Force criteria (ITF) and the 2020 Padua criteria. MethodsInclusion criteria were “definite” or “borderline” ACM diagnosed according to the “Padua criteria” in patients <18 years old. History, electrocardiograms, ECG-holter monitorings, exercise testings, imaging investigations, electrophysiological studies, genetic testings and follow-up data were collected. ResultsWe enrolled 21 patients (mean age 13.9 ± 2 years). Most of them presented for minor arrhythmias. Premature ventricular complexes burden was 7.9 ± 10%. Cardiac magnetic resonance (19/21, 90.5% patients) showed right ventricular (RV) dilatation, wall motion abnormalities and late gadolinium enhancement (LGE) of both ventricles as predominant features [in 9 patients (52.9%) LGE left ventricle]. Genetic results (19/21 patient) showed compound heterozygous variants in 3/19 patients (15.8%), digenic in 3/19 (15.8%) and single in 6/19 (31.6%). Cardiac defibrillator (ICD) was indicated in 15 patients (71.4%): 6 in class I, 7 in class IIa, 2 in class IIb. Appropriate shocks occurred in 2 patients (13.3%), follow-up 5.46 ± 3.17 years According to 2010 ITF criteria: among the 18 patients with a “definite” ACM diagnosis, one patient would have had a “borderline” diagnosis, three a “possible” diagnosis and one no diagnosis and among the three patients with “borderline” diagnosis two would have had a “possible” diagnosis. ConclusionsPediatric ACM can be diagnosed in the majority of cases secondary to incidental finding of simple ventricular arrhythmias. PVC burden is low and exercise induced arrhythmias rarely occur. Few patients with ICD experience appropriate shocks. “Padua criteria” improve the diagnostic accuracy.

Influence of the Type and Degree of Left Ventricular Hypertrophy on the Prevalence of Ventricular Arrhythmias in Patients with Hypertensive Heart Disease

To investigate the correlation between the prevalence of ventricular arrhythmias (VA) and the type and degree of left ventricular hypertrophy (LVH) in hypertensive patients using exercise testing and Holter monitoring. A total of 192 patients (87 men and 105 women) without coronary disease were divided into three groups according to type of LVH (concentric, eccentric, and asymmetric) and three subgroups in relation to the degree of hypertrophy (mild, moderate, and severe). In all subjects blood pressure was measured, electrocardiographic and echocardiographic data obtained and the prevalence of VA determined by Holter monitoring and bicycle ergometry. The most frequent LVH type was the concentric (63%), followed by eccentric (28%) and asymmetric (9%). Severe LVH was found in 10% of patients. Complex VA during Holter monitoring were identified in > 40% of patients. During the stress test this percentage increased by additional 7.4%. There was no statistically significant difference between groups in frequency of simple (p = 0.757) and complex (p = 0.657, p = 0.819, p = 0.617, for polytopic, pairs and ventricular tachycardia, respectively) VA. Increased prevalence of VA was found for the moderate and severe degree in all types. In the concentric type the difference was statistically significant for simple VA (p = 0.042). : There was no correlation between type of LVH and prevalence of VA. The severity of hypertrophy contributes more to a greater prevalence of VA than the LVH pattern. The combination of severe degree and concentric type carries the greatest cardiovascular risk.

Effect of thrombolytic therapy on occurrence of complex ventricular arrhythmias in the late hospitalization period in acute myocardial infarct: relation with long-term remodeling of the left ventricle

The impact of thrombolytic therapy on the incidence of complex ventricular arrhythmias is not yet clarified. The aim of this study was to investigate the impact of thrombolytic therapy on the incidence of complex ventricular arrhythmias, as well as long term association between complex ventricular arrhythmias and left ventricular remodelling, and their impact on five-year lethality. Ninety seven consecutive patients with first acute myocardial infarction (streptokinase was administered in 58 patients), underwent 24-hours Holter monitoring at discharge. Ventricular arrhythmias were classified according to Lown classification, and patients were grouped into the group with simple ventricular arrhythmias (Lown class 0 to 2), and the group with complex ventricular arrhythmias (Lown class 3 to 5). Echocardiography was performed at discharge, and six and twelve months after the infarction. Left ventricular volume indexes and ejection fraction was determined using Simpson's biplane formula. In patients with complex ventricular arrhythmias left ventricular volume indexes were higher and ejection fraction was lower throughout the study, whereas wall motion score index was higher one year after the infarction. On the other hand, these variables were similar throughout the follow-up within the groups of patients with and without complex ventricular arrhythmias who received thrombolytic therapy. The incidence of complex ventricular arrhythmias was similar in thrombolyzed and non-thrombolyzed patients (11/58 vs. 5/39). There was no difference in five year lethality between patients with and without complex ventricular arrhythmias (4/16 vs. 13/81 patients). Our data indicated that left ventricular remodelling in patients with complex ventricular arrhythmias was not progressive after hospital discharge. The presence of complex ventricular arrhythmias was not associated with the increased five-year lethality, despite of more pronounced left ventricular remodelling. It occurred that thrombolysis per se had no influence on the incidence of complex ventricular arrhythmias in the late hospital phase after the first acute myocardial infarction.

Arrhythmias and conduction disturbances after coronary artery bypass graft surgery: Epidemiology, management, and prognosis

CABG is associated with many perioperative complications, including supraventricular and ventricular arrhyhtmias and conduction disturbances. Atrial fibrillation occurs in <-40% of patients after CABG and is especially common in older patients. Although it is often benign and self-limited, it can lead to complications such as stroke. Treatment consists primarily of control of the ventricular response rate; in some cases, antiarrhythmic drugs or electrical cardioversioon are needed. Anticoagulation should be considered in appropriate cases of persistent (48 to 72 hours) atrial fibrillation after initial treatment. Prophylaxis, especially with β-blocking agents, seems to be effective and should be considered in appropriate cases. Simple ventricular arrhythmias are common after CABG and do not affect the patient's prognosis; however, sustained VT/VF occur infrequently (<2% of patients) and carry a high mortality rate. Treatment is aimed at correcting precipitating factors (e.g., myocardial ischemia). Electrophysiologically guided drug therapy and implantation of an ICD should be considered in appropriate cases for patients who survive the initial events. Transient minor conduction disturbances are common after CABG; in some patient persistent AV block and sinus node dysfunction develop and may require treatment with permanent pacemaker.

ECG variants and cardiac arrhythmias in athletes: Clinical relevance and prognostic importance

These findings permit the following conclusions on cardiac changes induced by high-performance sports and high levels of training. Sinus bradycardia and AV block can frequently be observed in athletes, but they do not require attention as long as they are asymptomatic or do not produce pauses exceeding 4 seconds. Persistent rather than transient second-degree AV block or Mobitz second- or third-degree AV block is an extremely unusual finding even in athletes and should be considered a sign of organic lesions until proved otherwise. Supraventricular and AV node ectopic beats are not more frequent in athletes than in the general population except for atrial fibrillation. WPW syndrome is of particular importance, since rapid conduction to the ventricle via the accessory AV pathway is possible, especially if there is a tendency toward atrial fibrillation. Likewise caution is required in athletes with hypertrophic cardiomyopathy. Here hemodynamic deterioration must be anticipated with the occurrence of supraventricular tachycardia. Simple ventricular arrhythmias occur among athletes with the same frequency as in the general population, but they usually disappear with exercise. The occurrence of complex ventricular forms of arrhythmia should always prompt cardiologic examination in search of underlying cardiac disease, particularly hypertrophic or dilated cardiomyopathy. The presence of ventricular arrhythmias without evidence of underlying heart disease does not indicate a special or increased risk of sudden cardiac death. A higher incidence of right and/or left ventricular hypertrophy, exercise-reversible ST elevation, and exercise-reversible changes in T waves (T negativity, sharp and/or excessive T waves) can be considered physiologic changes in the ECGs of athletes. These changes correlate closely with the type of sports activity and degree of training and are reversible when the activity is stopped. Horizontal ST segment depression are by contrast very rare in athletes and should always be clarified by cardiologic examination. Exercise-induced sudden cardiac death in athletes is unusual without preexisting heart disease. The cause of sudden cardiac death among athletes less than 40 years of age can be predominantely ascribed to congenital heart diseases (such as hypertrophic cardiomyopathy or coronary anomalies). In athletes more than 40 years of age and with increasing age, coronary heart disease is the most frequent autopsy finding. A corresponding risk stratification should take these partial dangers into account.

Ventricular arrhythmias after coronary artery bypass graft surgery: Incidence, risk factors and long-term prognosis

The incidence, risk factors and long-term prognosis of complex ventricular arrhythmias after coronary artery bypass graft surgery are not known. Complex ventricular arrhythmias are defined as Lown grades 4a (couplets), 4b (ventricular tachycardia) and 5 (R on T phenomenon). Ninety-two patients with normal left ventricular function who underwent elective coronary artery bypass graft surgery were prospectively evaluated. Ventricular arrhythmias were documented by predischarge 24 hour ambulatory electrocardiographic monitoring; 43% of patients had no or simple ventricular arrhythmias (Lown grades 1 to 3) and 57% had complex ventricular arrhythmias. Risk factors analyzed included age, sex, diabetes, hypertension, smoking, preoperative digoxin or propranolol therapy, cardiopulmonary bypass time, aortic cross-clamp time, number of vessels bypassed, peak creatine kinase (CK) elevation and pericarditis. No risk factor identified patients at higher risk for complex ventricular arrhythmias. Patients were followed up for 6 to 24 months (mean 16). Patients with complex ventricular arrhythmias did not have a higher incidence of sudden death, cardiac death, syncope, angina, myocardial infarction or cerebrovascular accident. It was concluded that: Complex ventricular arrhythmias are common after coronary artery bypass graft surgery. None of the risk factors considered identify high risk patients. Complex ventricular arrhythmias after coronary artery bypass graft surgery do not indicate a poor prognosis in patients with normal left ventricular function.

Arrhythmias in ischemic and nonischemic dilated cardiomyopathy: Prediction of mortality by ambulatory electrocardiography

To test the hypothesis that ventricular arrhythmias detected by ambulatory electrocardiography can stratify mortality risk in patients with ischemic and those with nonischemic dilated cardiomyopathy, clinical, hemodynamic and neurohumoral findings were evaluated in 31 patients. By Kaplan-Meier analysis, the total population had 51% survival at 12 months and 19% survival at 25 months. Subgroups based on peak complexity of ventricular arrhythmias included 9 patients with simple ventricular arrhythmias (peak Lown grades 1 to 3) and 22 patients with complex ventricular arrhythmias (peak Lown grades 4 or 5). Clinical variables and baseline catecholamine levels and renin-angiotensin system activity were similar in the simple and complex arrhythmia subgroups. Patients with simple and those with complex arrhythmias were comparable by all hemodynamic indexes except for a higher mean pulmonary capillary wedge pressure in the complex arrhythmia subgroup. Survival was strikingly related to arrhythmias: mortality was 11% (1 of 9) in the simple ventricular arrhythmia subgroup and 59% (13 of 22) in the complex ventricular arrhythmia subgroup (p < 0.025 by log-rank test). Twelve patients died suddenly and 2 patients died in circulatory failure, and the risk of death was not affected by the etiology of cardiomyopathy. The higher mortality among the patients with complex arrhythmia could not be explained by the presence of elevated filling pressures alone. Thus, ambulatory electrocardiography can stratify mortality risk among patients with severe ischemic and nonischemic dilated cardiomyopathy. These data are consistent with the hypothesis that complex ventricular arrhythmias represent an independent mortality risk factor in this population.

Prognostic value of ventricular arrhythmias associated with treadmill exercise testing in patients studied with cardiac catheterization for suspected ischemic heart disease

The prognostic information provided by ventricular arrhythmias associated with treadmill exercise testing was evaluated in 1,293 consecutive nonsurgically treated patients undergoing an exercise test within 6 weeks of cardiac catheterization. The 236 patients with simple ventricular arrhythmias (at least one premature ventricular complex, but without paired complexes or ventricular tachycardia) had a higher prevalence of significant coronary artery disease (57 versus 44%), three vessel disease (31 versus 17%) and abnormal left ventricular function (43 versus 24%) than did patients without ventricular arrhythmias. Patients with paired complexes or ventricular tachycardia had an even higher prevalence of significant coronary artery disease (75%), three vessel disease (39%) and abnormal left ventricular function (54%). In the 620 patients with significant coronary artery disease, patients with paired complexes or ventricular tachycardia had a lower 3 year survival rate (75%) than did patients with simple ventricular arrhythmias (83%) and patients with no ventricular arrhythmias (90%). Ventricular arrhythmias were found to add independent prognostic information to the noninvasive evaluation, including history, physical examination, chest roentgenogram, electrocardiogram and other exercise test variables (p = 0.03). Ventricular arrhythmias made no independent contribution once the cardiac catheterization data were known. In patients without significant coronary artery disease, no relation between ventricular arrhythmias and survival was found.