BACKGROUND: A relatively common complication of COVID -19 infection is arrhythmia. There is limited information about myocardial deformation and heart rate variability (HRV) in symptomatic post COVID patients presented by ventricular arrhythmia.
OBJECTIVE: Our goal was to assess 2D-ventricular strain and heart rate variability indices (evaluated by ambulatory ECG monitoring) in post-COVID-19 patients suffering from ventricular arrhythmia.
METHODS: The current observational case-control study performed on 60 patients one month after they had recovered from the COVID-19 infection. Thirty healthy volunteers served as the control group. Each participant had a full medical history review, blood tests, a 12-lead surface electrocardiogram (ECG), 24-h ambulatory ECG monitoring, and an echo-Doppler examination to evaluate the left ventricular (LV) dimensions, tissue Doppler velocities, and 2D-speckle tracking echocardiography (2D-STE) for both the LV and right ventricular (RV) strain.
RESULTS: Symptomatic post-COVID patients with monomorphic premature ventricular contractions (PVCs) showed a substantial impairment of LV/RV systolic and diastolic functions, LV/RV myocardial performance (MPI) with reduced indices of HRV. Patients with higher versus lower ventricular burden had poorer functional status, higher levels of inflammatory biomarkers and reduced parameters of HRV (New York Heart Association (NYHA) class: 2.1 ± 0.9 vs. 1.5 ± 0.6, p < 0.001, C-reactive protein (CRP): 13.3 ± 4.1 vs. 8.3 ± 5.9 mg/L, p < 0.0001, low frequency/high frequency (LF/HF): 3.6 ± 2.4 vs. 2.2 ± 1.2, p < 0.002, the root mean square of the difference between successive normal intervals (rMSSD): 21.8 ± 4.7 vs. 29.3 ± 14.9 ms, p < 0.039 and the standard deviation of the RR interval (SDNN): 69.8 ± 19.1 vs.108.8 ± 37.4 ms, p < 0.0001). The ventricular burden positively correlated with neutrophil/lymphocyte ratio (NLR) (r = 0.33, p < 0.001), CRP (r = 0.60, p < 0.0001), while it negatively correlated with LV-global longitudinal strain (GLS) (r = -0.38, p < 0.0001), and RV-GLS (r = -0.37, p < 0.0001).
CONCLUSIONS: Patients with post-COVID symptoms presented by ventricular arrhythmia had poor functional status. Patients with post-COVID symptoms and ventricular arrhythmia had subclinical myocardial damage, evidenced by speckle tracking echocardiography while having apparently preserved LV systolic function. The burden of ventricular arrhythmia in post-COVID patients significantly correlated with increased inflammatory biomarkers and reduced biventricular strain.

Cardiomyopathy is defined as structural and functional myocardial abnormality not attributed to ischemic, valvular, hypertensive, or congenital cardiac causes. The main phenotypes of cardiomyopathy include hypertrophic, dilated, non-dilated left ventricular, restrictive, arrhythmogenic right ventricular, Takotsubo, and left ventricular noncompaction cardiomyopathies. A significant proportion of dilated cardiomyopathy (DCM) cases represents patients with genetic mutations, most commonly titin gene truncating variants (TTNtv). It has been shown that TTNtv mutation contributes to the development of certain types of DCM such as alcohol, chemotherapy, and peripartum. We present a case of DCM where genetic workup revealed TTNtv without other contributing factors. The course was complicated by multiple ventricular tachycardias (VTs) refractory to medical management, despite treatment with amiodarone, sotalol, dofetilide, mexiletine, and propranolol. Interestingly, endocardial mapping failed to delineate the substrate of tachycardia. This report underscores the importance of genetic testing in DCM and highlights the potential association of titin cardiomyopathy with refractory VTs, possibly of epicardial origin.

BACKGROUND: Frequent premature ventricular contractions (PVCs) in children are usually considered benign. Symptoms and/or left ventricular dysfunction are indications for treatment with anti-arrhythmic drugs (AAD).
OBJECTIVE: To evaluate the efficacy of flecainide versus metoprolol in reducing PVCs in children.
METHODS: A randomized open label cross-over trial children with a PVC-burden of >15% on Holter; successively treated with metoprolol and flecainide or vice versa, with a drug free interval of at least two weeks. Holter measurements were repeated before and after the start of the AAD.
RESULTS: Sixty patients were screened, 19 patients could be included. Median age was 13.9 years (IQR 5.5 years). Mean baseline PVC-burden was 21.7% (N=18, SD±14.0) before the start of flecainide and 21.2% (N=17, SD±11.5) before the start of metoprolol. In a mixed model analysis the estimated mean reduction in PVC-burden was 10.6 percentage-points (95%-CI 5.8-15.3) for flecainide and 2.4 percentage-points (95%-CI -2.7-7.5) for metoprolol, with a significant difference of 8.2 percentage-points (95%-CI of 0.86-15.46, P=0.031). Exploratory analysis revealed that 9/18 patients treated with flecainide and 1/17 patients treated with metoprolol, had a reduction to a PVC-burden below 5%. No discriminating factors between flecainide-responders and non-responders were found; the mean plasma level was not significantly different (0.34 mg/L versus 0.52 mg/L, P=0.277).
CONCLUSIONS: In children with frequent PVCs flecainide led to a significant greater reduction of PVC-burden, compared to metoprolol. Flecainide was effective in only a subgroup of patients, which appears to be unrelated to the plasma level. (Dutch Trial Register number 26689).

Premature ventricular contractions (PVCs) are a common form of arrhythmic events, often representing an idiopathic and benign condition without further therapeutic interventions. However, in certain circumstances PVCs may represent the epiphenomenon of a concealed structural heart disease (SHD). Surface 12‑leads EKG and 24-h dynamic EKG are necessary to assess their main characteristics such as site of origin, frequency and complexity. Echocardiography represents the first-line imaging tool recommended to evaluate cardiac structures and function. Cardiac Magnetic Resonance (CMR) is recognized as a superior modality for detecting structural cardiac alterations, that might evade detection by conventional echocardiography. Moreover, in specific populations such as athletes, CMR may have a crucial role to exclude a concealed SHD and the risk of serious arrhythmic events during sport activity. Some clinical characteristics such as male sex, older age or family history of sudden cardiac death (SCD) or cardiomyopathy, and some electrocardiographic features of PVCs, in particular a right branch bundle block (RBBB) with superior/intermediate axis morphology, the reproducibility of VAs during exercise test (ET) or the evidence of complex ventricular arrhythmias, may warrant a CMR evaluation, due to the high probability of SHD. In this systematic review our objective was to provide an exhaustive overview on the role of CMR in detecting a concealed SHD in patients with high daily burden of PVCs and a normal echocardiographic evaluation, paving the way for a more extensive utilization of CMR in presence of certain high-risk clinical and/or EKG features identified during the diagnostic workup.

UNASSIGNED: Epidemiological studies have demonstrated that severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-positive patients often develop atrial fibrillation, premature ventricular contractions (PVCs), and conduction disorders. The manifestation of ventricular cardiac arrhythmias accentuates the risk of sudden cardiac death.
UNASSIGNED: A retrospective study was conducted on the cohort of 1,614 patients admitted for coronavirus disease 2019 (COVID-19). Patients were categorized into two groups based on the occurrence of PVCs. Group I comprised 172 patients diagnosed with PVCs of Lown-Wolf class II - IV upon hospital admission; group II (control group) consisted of 1,442 patients without this arrhythmia. Each patient underwent comprehensive clinical, laboratory, and instrumental evaluations.
UNASSIGNED: The emergence of PVCs in individuals afflicted with COVID-19 was associated with a 5.879-fold heightened risk of lethal outcome, a 2.904-fold elevated risk of acute myocardial infarction, and a 2.437-fold increased risk of pulmonary embolism. Upon application of diagnostic criteria to evaluate the \"cytokine storm\", it was discovered that the occurrence of the \"cytokine storm\" was notably more frequent in the group with PVCs, manifesting in six patients (3.5%), compared to 16 patients (1.1%) in the control group (P < 0.05). The mean extent of lung tissue damage in group I was significantly greater than that of patients in group II (P < 0.05). Notably, the average oxygen saturation level, as measured by pulse oximetry upon hospital admission was 92.63±3.84% in group I and 94.20±3.50% in group II (P < 0.05).
UNASSIGNED: The presence of PVCs in COVID-19 patients was found to elevate the risk of cardiovascular complications. Significant independent predictors for the development of PVCs in patients with SARS-CoV-2 infection include: age over 60 years (risk ratio (RR): 4.6; confidence interval (CI): 3.2 - 6.5), a history of myocardial infarction (RR: 3.5; CI: 2.6 - 4.6), congestive heart failure (CHF) with reduced left ventricular ejection fraction (RR: 5.5; CI: 3.9 - 7.6), respiratory failure (RR: 2.3; CI: 1.7 - 3.1), and the presence of a \"cytokine storm\" (RR: 4.5; CI: 2.9 - 6.0).

OBJECTIVE: Changes in myocardial mitochondrial morphology and function in premature ventricular contractions (PVCs)-induced cardiomyopathy (PVCCM) remain poorly studied. Here, we investigated the effects of PVCs with different coupling intervals (CIs) on myocardial mitochondrial remodelling in a canine model of PVCCM.
RESULTS: Twenty-one beagles underwent pacemaker implantation and were randomised into the sham (n = 7), short-coupled PVCs (SCP, n = 7), and long-coupled PVCs (LCP, n = 7) groups. Right ventricular (RV) apical bigeminy was produced for 12-week to induce PVCCM in the SCP (CI, 250 ms) and LCP (CI, 350 ms) groups. Echocardiography was performed at baseline and biweekly thereafter to evaluate cardiac function. Masson\'s trichrome staining measured ventricular interstitial fibrosis. The ultrastructural morphology of the myocardial mitochondria was analysed using transmission electron microscopy. Mitochondrial Ca2+ concentration, reactive oxygen species (ROS) levels, adenosine triphosphate (ATP) content, membrane potential, and electron transport chain (ETC) complex activity were measured to assess myocardial mitochondrial function. Twelve-week-PVCs led to left ventricular (LV) enlargement with systolic dysfunction, disrupted mitochondrial morphology, increased mitochondrial Ca2+ concentration and ROS levels, decreased mitochondrial ATP content and membrane potential, and impaired ETC complex activity in both the SCP and LCP groups (all p < 0.01 vs the sham group). Ventricular fibrosis was observed only in canines with LCP. Worse cardiac function and more pronounced abnormalities in mitochondrial morphology and function were observed in the LCP group than to the SCP group (all p < 0.05).
CONCLUSIONS: We demonstrated myocardial mitochondrial abnormalities in dogs with PVCCM, characterised by abnormal mitochondrial morphology, mitochondrial Ca2+ overload, oxidative stress, and impaired mitochondrial energy metabolism. Compared to SCP, long-term LCP exposure resulted in more severe mitochondrial remodelling and cardiac dysfunction in dogs.

Arrhythmias frequently accompany heart failure and left ventricular dysfunction. Tachycardias, atrial fibrillation, and premature ventricular contractions can induce a reversible form of dilated cardiomyopathy (CM) known as arrhythmia-induced CM (AiCM). The intriguing question is why certain individuals are more susceptible to AiCM, despite similar arrhythmia burdens. The primary challenge is determining the extent of arrhythmias\' contribution to left ventricular systolic dysfunction. AiCM should be considered in patients with a mean heart rate of >100 beats/min, atrial fibrillation, or a PVC burden of >10%. Confirmation of AiCM occurs when CM reverses upon eliminating the responsible arrhythmia. Therapy choice depends on the specific arrhythmia, patient comorbidities, and preferences. After left ventricular function is restored, ongoing follow-up is essential if an abnormal myocardial substrate persists. Accurate diagnosis and treatment of AiCM have the potential to enhance patients\' quality of life, improve clinical outcomes, and reduce hospital admissions and overall health care costs.

UNASSIGNED: The treadmill exercise test is widely used to determine cardiovascular risk and mortality. Premature ventricular complexes (PVCs) are frequently observed during exercise stress testing. The literature on the role of PVCs observed during treadmill exercise testing in predicting prognosis is controversial. Hence, we aimed to evaluate the clinical results of PVCs seen during exercise testing in patients without obstructive coronary artery disease confirmed by coronary angiography (CAG).
UNASSIGNED: The study population consisted of 1624 consecutive patients who were considered high risk according to the Duke treadmill risk score and had no significant stenosis on CAG from January 2016 to April 2021. The primary endpoints of the study were long-term all-cause mortality of patients who had PVCs during the exercise test or during the resting phase.
UNASSIGNED: Long-term mortality was observed in 53 of the 1624 patients after a mean follow-up of 47 months. PVCs were observed in 293 (18.7%) patients without long-term mortality, and in 24 (45.3%) patients with long-term mortality (p < 0.001). The model adjusted for all covariates showed that the presence of PVCs in the recovery phase [p < 0.007, hazard ratio (HR) (95% confidence interval (CI)) 2.244 (1.244-4.047)] and advanced age [p < 0.001, HR (95% CI) 1.194 (1.143-1.247)] were associated with long-term all-cause mortality.
UNASSIGNED: PVCs observed during treadmill exercise testing and the recovery phase were related to long-term mortality in patients without obstructive coronary artery disease.

BACKGROUND: Premature ventricular contractions (PVCs) are a common cardiac condition often associated with disabling symptoms and impaired quality of life (QoL). Current treatment strategies have limited effectiveness in reducing symptoms and restoring QoL for patients with PVCs. Symptom preoccupation, involving cardiac-related fear, hypervigilance, and avoidance behavior, is associated with disability in other cardiac conditions and can be effectively targeted by cognitive behavioral therapy (CBT).
OBJECTIVE: The aim of this study was to evaluate the effect of a PVC-specific CBT protocol targeting symptom preoccupation in patients with symptomatic idiopathic PVCs.
METHODS: Nineteen patients diagnosed with symptomatic idiopathic PVCs and symptom preoccupation underwent PVC-specific CBT over 10 weeks. The treatment was delivered by a licensed psychologist via videoconference in conjunction with online text-based information and homework assignments. The main components of the treatment were exposure to cardiac-related symptoms and reducing cardiac-related avoidance and control behavior. Self-rated measures were collected at baseline, post treatment, and at 3- and 6-month follow-ups. The primary outcome was PVC-specific QoL at posttreatment assessment measured with a PVC-adapted version of the Atrial Fibrillation Effects on Quality of Life questionnaire. Secondary measures included symptom preoccupation measured with the Cardiac Anxiety Questionnaire. PVC burden was evaluated with 5-day continuous electrocardiogram recordings at baseline, post treatment, and 6-month follow-up.
RESULTS: We observed large improvements in PVC-specific QoL (Cohen d=1.62, P<.001) and symptom preoccupation (Cohen d=1.73, P<.001) post treatment. These results were sustained at the 3- and 6-month follow-ups. PVC burden, as measured with 5-day continuous electrocardiogram, remained unchanged throughout follow-up. However, self-reported PVC symptoms were significantly lower at posttreatment assessment and at both the 3- and 6-month follow-ups. Reduction in symptom preoccupation had a statistically significant mediating effect of the intervention on PVC-specific QoL in an explorative mediation analysis.
CONCLUSIONS: This uncontrolled pilot study shows preliminary promising results for PVC-specific CBT as a potentially effective treatment approach for patients with symptomatic idiopathic PVCs and symptom preoccupation. The substantial improvements in PVC-specific QoL and symptom preoccupation, along with the decreased self-reported PVC-related symptoms warrant further investigation in a larger randomized controlled trial.
BACKGROUND: ClinicalTrials.gov NCT05087238; https://clinicaltrials.gov/study/NCT05087238.

OBJECTIVE: Arrhythmia-induced cardiomyopathy (AiCM) represents a subtype of acute heart failure (HF) in the context of sustained arrhythmia. Clear definitions and management recommendations for AiCM are lacking. The European Heart Rhythm Association Scientific Initiatives Committee (EHRA SIC) conducted a survey to explore the current definitions and management of patients with AiCM among European and non-European electrophysiologists.
RESULTS: A 25-item online questionnaire was developed and distributed among EP specialists on the EHRA SIC website and on social media between 4 September and 5 October 2023. Of the 206 respondents, 16% were female and 61% were between 30 and 49 years old. Most of the respondents were EP specialists (81%) working at university hospitals (47%). While most participants (67%) agreed that AiCM should be defined as a left ventricular ejection fraction (LVEF) impairment after new onset of an arrhythmia, only 35% identified a specific LVEF drop to diagnose AiCM with a wide range of values (5-20% LVEF drop). Most respondents considered all available therapies: catheter ablation (93%), electrical cardioversion (83%), antiarrhythmic drugs (76%), and adjuvant HF treatment (76%). A total of 83% of respondents indicated that adjuvant HF treatment should be started at first HF diagnosis prior to antiarrhythmic treatment, and 84% agreed it should be stopped within six months after LVEF normalization. Responses for the optimal time point for the first LVEF reassessment during follow-up varied markedly (1 day-6 months after antiarrhythmic treatment).
CONCLUSIONS: This EHRA Survey reveals varying practices regarding AiCM among physicians, highlighting a lack of consensus and heterogenous care of these patients.