48-hour ambulatory electrocardiography in dynamite workers and controls.

The Rhythms of Aging: What New Do We Know from Holter Monitoring?

The long-term outcome of athletes with frequent ventricular premature complexes (VPCs) and apparently normal heart has not been fully clarified. To evaluate the clinical and prognostic significance of VPCs and the influence of continuing sports activity during follow-up, we studied 120 healthy athletes (96 men; median age 16 years) in whom frequent VPCs (>100 VPCs/24 hours) were discovered by chance during preparticipation screening. All athletes were followed up for a median of 84 months. During follow-up, 96 underwent serial 24-hour Holter recording and 62 underwent serial echocardiography. The median number of VPCs/24 hours on basal Holter was 3,760. During follow-up, 81 athletes continued sports activity, whereas 39 did not. No athlete died or developed overt heart disease. The median number of VPCs/24 hours decreased in both athletes who continued sports activity and those who did not (from 3,805 to 1,124, p <0.0001 and from 5,787 to 1,298, p <0.0001, respectively). During follow-up, left ventricular ejection fraction slightly decreased to <55% in 9 of 62 athletes who, in respect to the remaining 53, had more VPCs/24 hours both in the basal state (12,000 vs 3,880) and during follow-up (10,702 vs 1,368), and a longer follow-up (95 vs 36 months). In conclusion, (1) frequent VPCs in athletes without heart disease have a long-term benign prognostic significance, (2) sporting activity does not modify this benign outcome, (3) during follow-up, the burden of VPCs decreases whether or not subjects continue sports activity, and (4) in 14.5% of athletes, ejection fraction slightly decreases over time.

Effect of premature ventricular beats on manual and automatic repolarization measurements

Funding Acknowledgements Type of funding sources: None. Introduction Heart involvement in systemic sclerosis patients is frequent and represents a negative prognostic factor with around 25% of SSc patients dying from cardiovascular related causes. Cardiac arrhythmias represent 6% of the overall causes of death in SSc patients. Not only a plethora of conditions typical of the disease seem to favour the presence of an arrhythmic substrate such as microvascular disease or fibrosis but autoimmunity itself has been recognized as a pathogenic mechanism for cardiac arrhythmias. Purpose The aim of our study was to investigate the incidence of arrhythmias in patients with systemic sclerosis and identify potential predictors. Methods Prospective longitudinal study enrolling all consecutive patients with a diagnosis of SSc and no overt cardiac disease nor pulmonary hypertension. Echocardiographic parameters and GLS were obtained at baseline and at each follow up as well as 12 lead ECG. Presence of atrial fibrillation (AF), atrial tachycardia (AT), ventricular ectopic beats &amp;gt;1000/24 h (VEB), supraventricular ectopic beats (SVEB), bundle branch block (BBB) and atrioventricular block (AVB) was registered. Results 160 patients (144 females, 90%, mean age 59±14 years) were enrolled from June 2016 to December 2021. At enrolment, 11.3% of patients with SSc presented a previous history of supraventricular arrhythmia (5.6% supraventricular ectopic beats, 3.1% atrial fibrillation, 2.5% atrial flutter) and 5.6% a history of ventricular arrhythmia (5.0% ventricular ectopic beats, 0.6% ventricular tachycardia). After a median follow-up of 3.1 years (95% CI 1.4-4.8 years), five patients (3.1%) died of cardiovascular causes, of which three (1.8%) experienced a sudden cardiac death. During the same period, 16 patients (10%) presented a new diagnosis of supraventricular arrythmia (8.7% atrial fibrillation, 1.3% atrial flutter) and two patients (1.2%) a new diagnosis of ventricular tachycardia. PR interval significantly increased during the 3.1-year follow-up (154±27 vs. 178±32 ms; p=0.013), as well as corrected QT interval (420±23 vs. 436±19 ms; p=0.001). New diagnosis of complete right and left bundle branch block was made in 18 (11.2%) and two (1.2%) of all SSc patients. Diagnosis of pulmonary arterial hypertension was associated with a 4-fold and a 10-fold increased risk of supraventricular and ventricular arrhythmias, respectively (Figure 1). A diffuse SSc variant (p=0.049), indexed right (p=0.020) and left atrial volumes (p=0.035), and E/E’ ratios (p=0.016) were all associated with an increased risk of supraventricular arrhythmias. TAPSE (p=0.040), as well as right (p=0.030) global longitudinal strain were associated with an increased risk of ventricular arrhythmias. Conclusions Ssc patients are often by an arrhythmic profile with an increased risk of supraventricular and ventricular events as well as sudden cardiac death. A comprehensive cardiological work up may help in lowering the risk of arrhythmic complications.

Permanent cardiac pacing is well established for the improvement of prognosis and quality of life in patients with severe bradycardia. However, sudden cardiac death still remains an unresolved problem, as it occurs in approximately 20-30% of paced patients. This 2-year follow-up study was directed at prospectively assessing prevalence, circumstances, and mechanisms of sudden death in 2,021 permanently paced patients. During the observation period, 220 patients (11%) died (mean pacing interval, 50.5 +/- 7 months). Lethal cerebrovascular events in 66 of 220 patients (30%) and sudden death in 49 of 220 patients (23%) were the two most frequently reported modes of death. Nonsudden (first year, 20%; subsequent years, 6.9%; p less than 0.01) and sudden death mortality rate (4% versus 1.8%, p less than 0.05) were highest during the first year. Mortality was unrelated to the patient's activity status at the time of death. Sudden cardiac death occurred more often in male patients (increased risk, 1.7 versus female patients; p less than 0.001) and patients younger than 60 years of age (5.2 versus patients older than 60 years, p less than 0.001). Patients with severe bradycardia (sudden death rate, 28%), severe atrioventricular block (25%), or atrial fibrillation with low ventricular rate (25%) before pacemaker implantation were more likely to suffer from sudden cardiac death than patients with previous syncopal attacks (sudden death rate, 15%) or sick sinus syndrome (17%). The highest incidence of sudden death was observed in patients with bifascicular and trifascicular bundle branch block. In this group, 35% of patients died suddenly during the follow-up period compared with 18% of patients without bundle branch block. In a subsequent study in 90 consecutive patients with various types of bundle branch block, undersensing of up to 13% of ectopic ventricular beats occurred in patients with bifascicular block. Pacing-induced tachyarrhythmias and ventricular fibrillation were documented in 10% of undersensed ectopic ventricular beats as well as in the setting of atrial fibrillation associated with ventricular arrhythmias. Young age, male sex, and a severely diseased heart indicated by the presence of bifascicular and trifascicular bundle branch block are the strongest predictive clinical parameters for sudden cardiac death, especially in the first year after pacemaker implantation.

Цель – определить частоту отдельных видов аритмий и нарушений проводимости сердца в российской популяции больных системной склеродермией (ССД) по данным стандартной и суточной электрокардиографии (ЭКГ) и оценить корреляции этих изменений с клиническими параметрами заболевания. Материал и методы. В исследование были включены 80 больных ССД и 60 сопоставимых с ними по полу и возрасту условно здоровых лиц, составивших контрольную группу. Всем участникам исследования проводили стандартную ЭКГ в покое и суточное холтеровское мониторирование (ХМ) ЭКГ. Результаты. При стандартной ЭКГ у больных ССД нарушения ритма определялись в 14 (17,5%) случаях, в том числе синусовая аритмия – у 2 больных и экстрасистолия – у 13 (16%). Частота наджелудочковой и желудочковой экстрасистолии составила 5 (6%) и 7 (9%) случаев соответственно; в 1 наблюдении отмечалось сочетание наджелудочковых и желудочковых экстрасистол. У 9 (11%) больных ССД выявлялись ЭКГ-признаки очагового фиброза миокарда различной локализации. ХМ ЭКГ показало высокую частоту наджелудочковых и желудочковых экстрасистол, которые выявлялись у 40 и 65% больных ССД соответственно. Частота и выраженность аритмий сердца у больных ССД была достоверно больше, чем в контрольной группе. У 36% больных отмечаются потенциально опасные в отношении раз- вития злокачественной аритмии и внезапной сердечной смерти желудочковые экстрасистолы высокой градации. Заключение. Нарушения ритма и проводимости сердца развиваются у большинства больных ССД. Стандартная ЭКГ не отражает истинную частоту аритмий сердца у больных ССД. Суточное ХМ ЭКГ является обязательным методом обследования больных ССД и контроля эффективности лечения.

this study aims to evaluate the prevalence of various arrhythmias and other electrocardiographic patterns within the group of individuals with overweight and obesity. One hundred eighty-one adults (90 females and 91 males) were qualified for inclusion in the experimental group. All participants had a body mass index (BMI) exceeding 25 kg/m2 (98 patients with obesity and 83 with overweight). The mean BMI in the obesity group was 33.6 kg/m2, and all participants had class 1 obesity. The control group comprised 69 individuals (56 females and 13 males) with normal BMI. The basic measurements were performed, and the participants filled out questionnaires describing their health conditions and lifestyles. Each participant underwent an electrocardiographic (ECG) examination and a 24 h Holter ECG examination. In patients with class 1 obesity compared to the control patients, the average numbers of premature ventricular beats (PVBs) and premature supraventricular beats (SPBs) were statistically significantly higher (p = 0.030 and p = 0.042). There was a positive correlation between body weight and PVB (p = 0.028) and between body weight and SPB (p = 0.028). Moreover, BMI and waist circumference were correlated with SPB (p = 0.043 and p = 0.031). In the backward stepwise multivariate regression model considering 24 h Holter ECG monitoring, concerning SPB as the dependent variable, it was observed that BMI (especially obesity class 1), type 2 diabetes, and thyroid disease exhibited the highest regression coefficients. obesity, even in class 1, might be a factor in a more frequent occurrence of abnormalities in electrocardiographic tests.

Objective — Monomorphic ventricular tachycardias (MVT) frequently occur in the acute phase of myocardial infarction (MI). In the past, some studies aimed to investigate the initiation pattern of ventricular tachycardias, although not in acute MI patients.The aim of the present study was to analyse the initiation pattern of MVT in acute MI using rhythm strips.Methods — This study utilized data on 255 rhythm strips defined as MVT, from 173 patients with acute ST-segment elevation MI. Monomorphic ventricular tachycardias that were not preceded by ventricular ectopic beats were defined as sudden onset MVT. Monomorphic ventricular tachycardias which were preceded by a single or multiple ectopic beats, including a short-long-short sequence, were defined as non-sudden onset MVT.Results — Non-sudden onset episodes were more common than sudden onset episodes (172 episodes, 67.4% versus 83 episodes, 32.5%).The morphology of the ventricular ectopic beat initiating tachycardia was similar to the first beat of MVT in 127 episodes (73.8%), but not in the remaining 45 episodes (26.1%). In the non-sudden onset group, 117 episodes (68%) initiated with a single ectopic beat, while 55 episodes (32%) initiated with multiple complexes.The left ventricular ejection fraction of the patients with non-sudden onset MVT was lower (50 ± 6 versus 56 ± 5, P< 0.05). Monomorphic ventricular tachycardias with no sudden onset also had shorter coupling intervals (CI) (P< 0.001) and shorter prematurity index (PI) (P< 0.001) than MVT with sudden onset. Similarly, the ventricular tachycardia cycle length was shorter in the group of MVT subjects with nonsudden onset as compared with sudden onset (P< 0.05). In contrast, tachycardias with sudden onset were associated with a shorter preceding RR interval (P< 0.01).Conclusions — Analysis of rhythm strips demonstrated that MVT is most often preceded by ventricular ectopic beats in the acute phase of MI.

Perioperative management of severe head injury in a patient with arrhythmogenic right ventricular dysplasia.

The detection of ventricular ectopic beats (VEB) in Electrocardiogram (ECG) plays a vital role in the diagnosis of cardiovascular diseases like ventricular tachycardia and ventricular fibrillation, which causes sudden death. This paper discusses the beat interval based features for the automated detection of ventricular ectopic beats. Five-time domain features, pre RR interval, post RR interval, QRS width, QR slope and RS slope are considered and a KNN classifier is employed to classify normal and ventricular ectopic beats. The proposed study make use of ECG signals derived from MIT-BIH arrhythmia database. The quantitative results are compared with qualitative assessment recorded already in the database. The overall classification accuracy achieved is 98.67% and the accuracy for normal & ventricular ectopic beats is 98.81% & 95.12% respectively with the Sensitivity of 95.12%, Specificity of 99.11% and Positive Predictivity of 92.85%.

Background A subset of patients with mitral valve prolapse (MVP) are at risk of life-threatening ventricular arrhythmias (VAs), and a high burden of premature ventricular contractions (PVCs) is associated with increased mortality in patients with MVP. Previous studies indicate that PVC burden could either increase with increasing heart rate (HR), decrease with increasing HR, or with no relationship to HR. The association between PVC burden and HR in MVP is not known, nor if there is an association with VAs. Purpose We aimed to explore the relationship between PVC burden and HR in patients with MVP. Furthermore, we aimed to explore whether the different PVC profiles were associated with severe VA. Methods In this cross-sectional ambispective outcome study, we included patients with MVP and available Holter monitorings with &amp;gt;100 PVCs per 24-hours seen at our tertiary centre. The Holter monitoring with the highest PVC burden was used in case of multiple recordings. We investigated the relationship between hourly PVC burden and hourly mean HR by univariable mixed linear regression. We defined PVC profiles as (1) fast-HR-dependent-PVC (F-HR-PVC) when there was a significant positive correlation, (2) slow-HR-dependent-PVC (S-HR-PVC) when there was a significant negative correlation, and (3) independent-HR-PVC (I-HR-PVC) when no correlation between PVC and HR was found. The significance was set to 0.05. Severe VA was defined as sustained ventricular tachycardia, non-sustained ventricular tachycardia with haemodynamic instability, ventricular fibrillation, aborted cardiac arrest, or appropriate shock by a primary preventive implantable cardioverterefibrillator. Severe VA was recorded from retrospective medical history, prospective ICD interrogation or monitoring with implantable loop recorder. Results We included 75 patients with &amp;gt;100 PVCs at Holter monitoring (median age 48 years [IQR 35-58], 58% female). The median PVC burden was 1.9% per 24-hours (IQR 0.4-7.2). We found F-HR-PVC in 49 patients (65%), S-HR-PVC in 1 (1%), and I-HR-PVC in 25 (33%). Twelve (16%) patients had severe VA and these had higher PVC burden compared to those without severe VA (7.3% per 24-hours [IQR 4.2-10.4] vs 1.1% per 24-hours [IQR 0.3-5.3], p=0.004). The median PVC burden was 1.5% (IQR 0.3-8.0) for F-HR-PVC, 5.7% for S-HR-PVC and 1.5% (IQR 0.3-8.0) for I-HR-PVC. We found no association between different PVC profiles and the presence of severe VA (F-HR-PVC 65% vs 67%, S-HR-PVC 2% vs 0%, I-HR-PVC 33% vs 33%, p&amp;gt;0.05 for all groups). Conclusion Fast-HR-dependent-PVC was most common in MVP patients, and slow-HR-dependent-PVC were rare. A higher PVC burden was associated with severe VA. However, different PVC profiles did not infer higher risk of severe VA in our study. Further studies are needed to explore whether distinct PVC profiles can predict severe VA in larger patient populations.

Effect of antihypertensive treatment on the prevalence of ventricular arrhythmias among patients with isolated systolic hypertension without left ventricular hypertrophy

Objective. The arrhythmia identification method based on the U-net has the potential for fast application. The RR-intervals have been proven to improve the performance of single-heartbeat identification methods. However, because both the heartbeats number and location in the input of the U-net are unfixed, the approach based on the U-net cannot use RR-intervals directly. To solve this problem, we proposed a novel method. The proposed method also can identify heartbeats of four classes, including non-ectopic (N), supraventricular ectopic beat (SVEB), ventricular ectopic beat (VEB), and fusion beat (F). Approach. Our method consists of the pre-processing and the two-stage identification framework. In the pre-processing part, we filtered input signals with a band-pass filter and created the auxiliary waveforms by RR-intervals. In the first stage of the framework, we designed a network to handle input signals and auxiliary waveforms. We proposed a masking operation to separate the input signal into two signals according to the result of the network. The first signal contains heartbeats of SVEB and VEB. The second signal includes heartbeats of N and F. The second stage consists of two networks and can further identify the heartbeats of SVEB, VEB, N, and F from these two signals. Main result. We validated our method on the MIT-BIH arrhythmia database with the inter-patient model. For classes N, SVEB, VEB, and F, our approach achieved F1 scores of 98.26, 68.61, 95.99, and 47.75, respectively. Significance. Our method not only can effectively utilize RR intervals but also can identify multiple arrhythmias.

Clinical observations indicate that increased QT interval dispersion in sinus beats may portend malignant ventricular arrhythmias and sudden cardiac death. The purpose of this study was to test the hypothesis that measures of QT dispersion in ventricular premature beats (QTd-V) may be also useful in identifying patients at high risk of arrhythmic events. In the group of 303 patients with ventricular premature beats on standard 12-lead ECG, the QTd-V was calculated as a difference between maximum and minimum QT interval in premature ventricular beats. During follow-up for 26 +/- 19 months the arrhythmic events (sustained ventricular tachycardia, ventricular fibrillation or sudden cardiac death) were noted in 42 patients. Patients with arrhythmic events had significantly (P < 0.005) greater values of QTd-V than those without arrhythmic events. Univariate predictors of arrhythmic events included QTd-V > or = 100 ms, left ventricular ejection fraction < 40%, QRS complex duration of ventricular premature beats > 150 ms, underlying heart disease and complete bundle branch block. Multivariate analysis using the Cox proportional hazard model showed that only QTd-V > or = 100 ms and ejection fraction < 40% were independent predictors of arrhythmic events. The results of this study indicate a significant relationship between QTd-V and the risk of arrhythmic events. The assessment of QTd-V may be useful for identifying patients with ventricular premature beats at high and low risk of subsequent arrhythmic events.

Significant Premature Ventricular Complex Burden Causing Dilated Cardiomyopathy/Heart Failure: A Case Report