Risk Stratification For Sudden Death Research Articles

Multimodality Imaging in Hypertrophic Cardiomyopathy for Risk Stratification.

In hypertrophic cardiomyopathy, multimodality imaging is crucial to confirm diagnosis, assess for presence and mechanism of left ventricular outflow tract obstruction, and risk stratification for sudden cardiac death. This review will focus on the application of imaging to assess established and emerging factors to be considered in sudden cardiac death risk stratification.

Primary prevention of sudden cardiac death in patients with tetralogy of Fallot with implantable cardioverter defibrillator: Insights from the DAI-T4F study

Ventricular arrhythmias and sudden death are feared late complications in patients with tetralogy of Fallot. Selection of candidates for primary prevention implantable cardioverter defibrillator (ICD) remains challenging. To identify patients with tetralogy of Fallot at high-risk of sudden cardiac death in primary prevention. The DAI-T4F study is an ongoing national French registry including all patients with tetralogy of Fallot and ICD ( NCT03837574 ). Information have been collected prospectively since 2010. Cox proportional hazard models were used to identify factors associated with appropriate ICD therapies. Among 134 patients enrolled, 47 (35.1%) underwent ICD implantation for primary prevention (median age 49.1 years, 76.6% males). At baseline, 20 (42.6%) patients had NSVT, 17 (36.2%) had altered LVEF ≤ 35%, 16 (34.0%) had positive programmed ventricular stimulation, and 16 (34.0%) had QRS duration ≥ 180ms. During a median (IQR) follow-up duration of 5.3 (2.1–8.0) years, 14 (29.8%) patients had at least one appropriate ICD therapy. The annual incidence of appropriate ICD therapies were 2.8%, 4.6%, 6.3%, and 8.6% in patients with none, one, two, or ≥ three of these factors ( P for trend = 0.145). None of predictors, considered isolated, was significantly associated with ICD appropriate therapies. Patients with non-sustained ventricular tachycardia (NSVT) and positive programmed ventricular stimulation had a significant increased risk of ICD appropriate therapies (HR = 3.8, 95% CI: 1.1–14.3, P = 0.035), as well as patients with NSVT and QRSd ≥ 180 ms (HR = 7.2, 95% CI: 1.6–32.7, P = 0.003). No patient with severe altered LVEF without other risk factor had appropriate ICD therapy. Our data illustrate that specific risk stratification and primary prevention for sudden cardiac death in patients with tetralogy of Fallot may be improved. The value of a severely altered LVEF appears low in the absence of other risk factors.

Electrocardiographic predictors of appropriate implantable cardioverter defibrillator therapies in patients with tetralogy of Fallot

The electrocardiogram (ECG) is widely available and may contribute to a better risk stratification for sudden cardiac death in tetralogy of Fallot. To identify ECG predictors of appropriate therapies in patients with tetralogy of Fallot and implantable cardioverter defibrillator (ICD). The DAI-T4F study is an ongoing national French registry including all patients with tetralogy of Fallot and ICD ( NCT03837574 ). Information have been collected prospectively since 2010. Cox proportional hazard models were used to identify factors associated with appropriate ICD therapies. A total of 134 patients (median age 41.7 years, 70.7% males) were enrolled. During a median (IQR) follow-up of 6.1 (2.7–10.2) years, 59 (44.0%) patients received at least one appropriate ICD therapy, giving annual incidence of 5.5% and 7.1% in primary and secondary prevention, respectively ( P = 0.058). Overall, QRSd ≥ 180ms ( P = 0.073), QRS fragmentation ( P = 0.052), and QRS vector magnitude (vm, P = 0.327) were not significantly associated with appropriate ICD therapies, whereas the association of QRSd ≥ 180ms and QRS fragmentation (HR = 1.9, 95% CI: 1.1–3.4, P = 0.036) were associated with an increased risk of appropriates ICD therapies. In patients with ICD for primary prevention (47 patients, 35.1%), while non-sustained ventricular tachycardia (NSVT) considered isolated was not associated with events during follow-up ( P = 0.069), combinations with QRSd ≥ 180 ms (HR = 7.2, 95% CI: 1.6–32.7, P = 0.011), QRS fragmentation (HR = 3.8, 95% CI: 1.2–12.4, P = 0.025), or decreased QRS vm (HR = 3.6, 95% CI: 1.1–12.1, P = 0.042) were all associated with a higher incidence of appropriate ICD therapies. Our findings highlight that cumulative risk score derived from ECG may contribute to improve risk stratification in patients with tetralogy of Fallot, in particular QRS fragmentation and QRS vm in association with QRS duration and other traditional risk factors.

Dialysis modality-related disparities in sudden cardiac death: hemodialysis versus peritoneal dialysis.

BackgroundPatients require risk stratification and preventive strategies for sudden cardiac death (SCD) based on the dialysis modality because the process of dialysis is a risk factor for SCD. This study aimed to compare the risk of SCD in patients undergoing hemodialysis (HD) versus peritoneal dialysis (PD).MethodsPatients on HD and PD were included in the end-stage renal disease registry of the Korean Society of Nephrology between 1985 and 2017. The incidence and associated factors of SCD were analyzed based on the dialysis modality.ResultsOf 132,083 patients, 34,632 (26.2%) died during 94.8 ± 73.6 months of follow-up. In patients on HD and PD, 22.2% and 19.6% of total deaths were SCDs. In the propensity score-matched population, SCD accounted for 21.7% and 19.6% of total deaths in patients on HD and PD, respectively. HD was independently associated with SCD even after adjusting for age and significant comorbidities. Hypertension, coronary artery disease, and congestive heart failure, and age at the time of death < 65 years were independent risk factors for SCD in patients on HD but not in those on PD. Diabetes was significantly associated with SCD regardless of the dialysis modality.ConclusionCompared with patients on PD, Korean patients on HD have a higher risk of SCD, which is attributable to cardiac comorbidities.

Positron emission tomography (15O-water, 11C-acetate, 11C-HED) risk markers and nonsustained ventricular tachycardia in hypertrophic cardiomyopathy

BackgroundThe objectives of the study were to describe positron emission tomography (PET) parameters, using the tracers 15O-water at rest/stress, 11C-acetate, and 11C-HED, with regard to nonsustained ventricular tachycardia (NSVT) in hypertrophic cardiomyopathy (HCM). PET offers quantitative assessment of pathophysiology throughout the left ventricular segments, including the endocardium/epicardium. The potential use PET in risk stratification remains to be elucidated. NSVT provides a marker for sudden cardiac death. MethodsPatients with a validated diagnosis of HCM who had an implantable cardioverter-defibrillator were interrogated at 12 months and independently of PET-examinations. ResultsIn total, 25 patients (mean age 56.8 ± 12.9 years, 76% males) were included and 10 reported NSVT. Mean myocardial blood flow (MBF) at rest was 0.91 ml/g/min and decreased at stress, 1.59 ml/g/min. The mean gradient (endocardium/epicardium quotient) at rest was 1.14 ± 0.09, while inverse at stress (mean 0.92 ± 0.16). Notably, MBF gradient at stress was significantly lower in patients with NSVT (p = 0.022) and borderline at rest (p = 0.059) while global MBF at rest and stress were not. Mean myocardial oxygen consumption (MVO2) was 0.088 ml/g/min (higher in NSVT, p = 0.023) and myocardial external efficiency 18.5%. Using 11C-HED, the mean retention index was 0.11 min−1 and a higher volume of distribution (p = 0.089) or transmural gradient of clearance rate (p = 0.061) or lower clearance rate (p = 0.052) showed a tendency of association of NSVT. ConclusionsThe endocardium/epicardium MBF gradient at stress is significantly lower in HCM patients with NSVT. This provides a novel approach to further refine risk stratification of sudden cardiac death.

Effectiveness of T wave alternans testing for risk stratification of ventricular tachyarrhythmias and sudden death in patients with cardiomyopathy

We present the case of a patient with typical atrial flutter treated with radiofrequency ablation of the cavo-tricuspid isthmus, which presented 5 days later with an ECG suggesting an atrial flutter recurrence. However, careful analysis of this ECG demonstrated a potentially different mechanism of the arrhythmia, underlying the importance of a pragmatic approach to ECG interpretation of arrhythmias. A secondary electrophysiological study was performed diagnosing a focal atrial tachycardia with origin at the coronary sinus ostium, in the presence of a blocked cavotricuspid isthmus. RF ablation successfully suppressed the arrhythmia.

Circulating miRNAs and Risk of SuddenDeath in Patients With CoronaryHeartDisease.

This study evaluated whether plasma miRNAs were specifically associated with sudden cardiac and/or arrhythmic death (SCD) in a cohort of patients with coronary heart disease (CHD), most of whom were without primary prevention implantable cardioverter-defibrillators. Novel biomarkers for sudden death risk stratification are needed in patients with CHD to more precisely target preventive therapies, such as implantable cardioverter-defibrillators. miRNAs have been implicated in regulating inflammation and cardiac fibrosis in cells, and plasma miRNAs have been shown to predict cardiovascular death in patients with CHD. We performed a nested case control study within a multicenter cohort of 5,956 patients with CHD followed prospectively for SCD. Plasma levels of 18 candidate miRNAs previously associated with cardiac remodeling were measured in 129 SCD cases and 258 control subjects matched on age, sex, race, and left ventricular ejection fraction. miR-150-5p, miR-29a-3p, and miR-30a-5p were associated with increased SCD risk (odds ratios and 95% confidence intervals: 2.03 [1.12 to 3.67]; p=0.02; 1.93 [1.07 to 3.50]; p=0.02; 0.55 [0.31 to 0.97]; p=0.04, respectively, for third vs. first tertile miRNA level). Unfavorable levels of all 3 miRNAs was associated with a 4.8-fold increased SCD risk (1.59 to 14.51; p=0.006). A bioinformatics-based approach predicted miR-150-5p, miR-29a-3p, and miR-30a-5p to be involved in apoptosis, fibrosis, and inflammation. These findings suggest that plasma miRNAs may regulate pathways important for remodeling and may be useful in identifying patients with CHD at increased risk of SCD.

Advanced Echocardiographic Imaging for Prediction of SCD in Moderate and Severe LV Systolic Function

ObjectivesThis study sought to determine the long-term prognostic value of myocardial deformation imaging by echocardiography in risk stratification of sudden cardiac death (SCD) and malignant ventricular arrhythmias (VAs) in a large consecutive cohort of patients with left ventricular (LV) systolic impairment, irrespective of its etiology. BackgroundLeft ventricular ejection fraction (LVEF) is limited for prediction of SCD. Echocardiographic strain-derived mechanical dispersion (MD) and global longitudinal strain (GLS) has been linked to VA and SCD. However, due to low event rates, the role of these parameters has not been fully elucidated. MethodsConsecutive clinically stable patients who underwent echocardiographic study performed in an outpatient setting from 2008 to 2014 with a Simpson left ventricular ejection fraction (LVEF) ≤45% were included in the study. Strain analysis was performed in which the LV was separated into 16 segments for regional analysis. Mechanical dispersion (MD) was calculated as the SD of the time to peak of each of the 16 regions. Outcome data were obtained from medical records. ResultsA total of 939 patients were included in the study, with median LVEF of 37% (interquartile range 30% to 42%). At follow-up (91.4 ± 23.4 months), 96 VA events had occurred. Multivariate analysis demonstrated that only MD ≥75 ms (hazard ratio: 9.45; 95% confidence interval: 4.75 to 18.81; p < 0.0001) was predictive of VA events. Low MD predicted a low event rate, irrespective of LVEF. ConclusionsUsing LVEF alone is inferior for prediction of VA and SCD, particularly in patients with moderately reduced LVEF. MD is easily obtained from standard echocardiographic images and can be used to improve risk prognosis, particularly in patients who are currently excluded from cardiac defibrillator insertion based on LVEF.

2395LGE CMR predicts sudden death and VT in adults with repaired tetralogy of Fallot - a prospective study with 3500 patient follow up years

Abstract Background Adults with repaired tetralogy of Fallot (rtoF) are at risk of ventricular arrhythmia and sudden cardiac death (SCD). Cross-sectional data suggest association of late gadolinium enhancement (LGE) cardiovascular magnetic resonance imaging (CMR) with adverse clinical risk factors Purpose We sought to determine prognosis related to LGE CMR. Methods In this prospective cohort study the primary composite outcome comprised the first of cardiovascular death (SCD or heart failure-related), aborted SCD (successfully resuscitated cardiac arrest or appropriate AICD shock for ventricular fibrillation), and clinical sustained ventricular tachycardia (VT&gt;30 seconds duration). Results In 531 rtoF patients (median age 32; 23–42, 296 (56%) male, NYHA≥II 17%) followed up after LGE CMR for median 5 (1.7–8.9) years, there were 39 primary composite outcomes: 10 SCD, 11 heart failure related deaths (2 perioperative RV failure), 2 aborted SCD and 16 clinical sustained VT events. At study end, there were 28 ventricular arrhythmic events in 28 rtoF patients (10 SCD, 16 clinical sustained VT, 2 aborted VF) that were significantly predicted by RV LGE extent (HR 1.45 CI: 1.3–1.6; P&lt;0.001). Univariable predictors of the primary outcome were RV LGE score; HR: 1.44 (1.31–1.57; p&lt;0.001), (Figure) together with older age; HR: 1.05 (1.02–1.07; P&lt;0.001), late repair; HR: 1.04 (1.02–1.07; p&lt;0.001), lower RV ejection fraction; HR: 0.92 (0.89–0.95; p&lt;0.001), larger RVOT akinetic length; HR: 1.04 (1.02–1.06; p&lt;0.001) larger right atrial area; HR: 1.2 (1.12–1.29; p&lt;0.001); higher BNP levels; HR: 1.01 (1–1.02; p&lt;0.001), lower peak VO2; HR: 0.89 (0.83–0.96; p=0.001), prior atrial arrhythmia; HR: 5.3 (2.8–10.07; p&lt;0.001), and non-sustained VT; HR: 4.1 (2.1–7.7; p&lt;0.001). Inducible VT did not predict the primary outcome; HR: 2.1 (0.57–8; p=0.25) In multivariable analysis both RV LGE score and indexed right atrial area (RAAi) only, remained predictive of the primary outcome (HR 1.29 CI: 1.12–1.49; p&lt;0.001 and HR 1.1 CI: 1.02–1.12; p=0.01, respectively). Patients could accordingly be stratified such that supramedian RV LGE score (≥5) and RAAi ≥16cm2/m2 had 5-year event free survival 84% vs 94% for supramedian RV LGE score (≥5) and RAAi &lt;16cm2/m2 or 98% for inframedian RV LGE score with RAAI&lt;16cm2/m2. Figure. Conclusions For every unit increase in CMR defined RV fibrosis score there is a 44% increased risk of sudden cardiac death and VT. LGE CMR and maximal right atrial area should therefore be incorporated into risk stratification for sudden death in adults with rTOF. Acknowledgement/Funding British heart foundation

Hypertrophic cardiomyopathy: genetics and clinical perspectives.

Hypertrophic cardiomyopathy (HCM) is the most common inherited heart disease and defined by unexplained isolated progressive myocardial hypertrophy, systolic and diastolic ventricular dysfunction, arrhythmias, sudden cardiac death and histopathologic changes, such as myocyte disarray and myocardial fibrosis. Mutations in genes encoding for proteins of the contractile apparatus of the cardiomyocyte, such as β-myosin heavy chain and myosin binding protein C, have been identified as cause of the disease. Disease is caused by altered biophysical properties of the cardiomyocyte, disturbed calcium handling, and abnormal cellular metabolism. Mutations in sarcomere genes can also activate other signaling pathways via transcriptional activation and can influence non-cardiac cells, such as fibroblasts. Additional environmental, genetic and epigenetic factors result in heterogeneous disease expression. The clinical course of the disease varies greatly with some patients presenting during childhood while others remain asymptomatic until late in life. Patients can present with either heart failure symptoms or the first symptom can be sudden death due to malignant ventricular arrhythmias. The morphological and pathological heterogeneity results in prognosis uncertainty and makes patient management challenging. Current standard therapeutic measures include the prevention of sudden death by prohibition of competitive sport participation and the implantation of cardioverter-defibrillators if indicated, as well as symptomatic heart failure therapies or cardiac transplantation. There exists no causal therapy for this monogenic autosomal-dominant inherited disorder, so that the focus of current management is on early identification of asymptomatic patients at risk through molecular diagnostic and clinical cascade screening of family members, optimal sudden death risk stratification, and timely initiation of preventative therapies to avoid disease progression to the irreversible adverse myocardial remodeling stage. Genetic diagnosis allowing identification of asymptomatic affected patients prior to clinical disease onset, new imaging technologies, and the establishment of international guidelines have optimized treatment and sudden death risk stratification lowering mortality dramatically within the last decade. However, a thorough understanding of underlying disease pathogenesis, regular clinical follow-up, family counseling, and preventative treatment is required to minimize morbidity and mortality of affected patients. This review summarizes current knowledge about molecular genetics and pathogenesis of HCM secondary to mutations in the sarcomere and provides an overview about current evidence and guidelines in clinical patient management. The overview will focus on clinical staging based on disease mechanism allowing timely initiation of preventative measures. An outlook about so far experimental treatments and potential for future therapies will be provided.

5204Primary prevention of sudden cardiac death in patients with tetralogy of Fallot with implantable cardioverter defibrillator: insights from the DAI-T4F study

Abstract Background Ventricular arrhythmias and sudden death are feared late complications in patients with tetralogy of Fallot. Selection of candidates for primary prevention implantable cardioverter defibrillator (ICD) remains challenging in this population. Non-sustained ventricular tachycardia (NSVT), altered left ventricular ejection fraction (LVEF), positive programmed ventricular stimulation, and enlarged QRS are currently used for risk stratification. Purpose To identify high-risk patients with tetralogy of Fallot in the setting of primary prevention of sudden cardiac death. Methods The DAI-T4F study is a large ongoing national French registry including all patients with tetralogy of Fallot and ICD (NCT03837574). Information have been collected prospectively since 2010 with annual update. Baseline patient characteristics and clinical events during the follow-up were analyzed with central adjudication. Cox proportional hazard models were used to identify factors associated with appropriate ICD therapies. Results Among 134 patients enrolled, 47 (35.1%) underwent ICD implantation for primary prevention (median age 49.1 years, 76.6% males). At baseline, 20 (42.6%) patients had NSVT, 17 (36.2%) had severe altered LVEF ≤35%, 16 (34.0%) had positive programmed ventricular stimulation, and 16 (34.0%) had QRS duration ≥180ms. Overall, 20 (42.6%), 15 (31.9%), and 6 (12.8%) patients had respectively one, two, or ≥ three of these risk factors. Six (12.8%) patients were implanted for other indications. During a median (IQR) follow-up duration of 5.3 (2.1–8.0) years, 14 (29.8%) patients had at least one appropriate ICD therapy. The annual incidence of appropriate ICD therapies were 2.8%, 4.6%, 6.3%, and 8.6% in patients with none, one, two, or ≥ three of these factors (p for trend = 0.145). None of predictors, considered isolated, was significantly associated with ICD appropriate therapies. Patients with non-sustained ventricular tachycardia (NSVT) and positive programmed ventricular stimulation had a significant increased risk of ICD appropriate therapies (HR=3.8, 95% CI: 1.1–14.3, p=0.035), as well as patients with NSVT and QRSd ≥180 ms (HR=7.2, 95% CI: 1.6–32.7, p=0.003). No patient with severe altered LVEF without other risk factor had appropriate ICD therapy. Patients with congestive heart failure and/or altered LVEF had a higher risk of non-sudden death or cardiac transplantation (HR=14.4, 95% CI: 1.8–112.7, p&lt;0.001). Seventeen (36.2%) patients experienced at least one ICD-related complication. Conclusions Our data illustrate that specific risk stratification and primary prevention for sudden cardiac death in patients with tetralogy of Fallot may be improved. The value of a severely altered LVEF appears low in the absence of other risk factors, and combination of different predictors is essential. The high rate of complications as well as consideration of competing risk situation have to be integrated in the benefit-risk equation.

5205Electrocardiographic predictors of appropriate implantable cardioverter defibrillator therapies in patients with tetralogy of Fallot

Abstract Background The electrocardiogram (ECG) is widely available and may contribute to a better risk stratification for sudden cardiac death in patients with tetralogy of Fallot. QRS duration has been consistently associated with outcomes, with a lack of specificity for sudden mortality and a relatively low predictive value. New markers such as QRS fragmentation and vectocardiographic parameters have been recently suggested. Purpose To identify ECG predictors of appropriate therapies in patients with tetralogy of Fallot and implantable cardioverter defibrillator (ICD). Methods The DAI-T4F study is a large ongoing national French registry including all patients with tetralogy of Fallot and ICD (NCT03837574). Information have been collected prospectively since 2010 with annual update. Baseline patient characteristics and clinical events during the follow-up were analyzed with central adjudication. Cox proportional hazard models were used to identify factors associated with appropriate ICD therapies. Results A total of 134 patients (median age 41.7 years, 70.7% males) were enrolled. During a median (IQR) follow-up of 6.1 (2.7–10.2) years, 59 (44.0%) patients received at least one appropriate ICD therapy, giving annual incidence of 5.5% and 7.1% in primary and secondary prevention, respectively (p=0.058). Overall, QRSd ≥180ms (p=0.073), QRS fragmentation (p=0.052), and QRS vector magnitude (vm, p=0.327) were not significantly associated with appropriate ICD therapies, whereas QRS fragmentation in right leads (HR=1.7, 95% CI: 1.1–2.9, p=0.039) and the association of QRSd ≥180ms and overall QRS fragmentation (HR=1.9, 95% CI: 1.1–3.4, p=0.036) were associated with an increased risk of appropriates ICD therapies. In patients with ICD for primary prevention (47 patients, 35.1%), 53.8% had QRS fragmentation, 48.6% had decreased QRS vm, and 41.0% had QRSd ≥180ms. In this group, while non-sustained ventricular tachycardia (NSVT) considered isolated was not associated with ventricular events during follow-up (p=0.069), respective combinations with QRSd ≥180 ms (HR=7.2, 95% CI: 1.6–32.7, p=0.011), QRS fragmentation (HR=3.8, 95% CI: 1.2–12.4, p=0.025), or decreased QRS vm (HR=3.6, 95% CI: 1.1–12.1, p=0.042) were all associated with a higher incidence of appropriate ICD therapies. Positive predictive value and negative predictive value were 0.33 and 0.85, 0.58 and 0.74, and 0.36 and 0.84 in patients with NSVT and QRS ≥180ms, NSVT and QRS fragmentation, and NSVT and decreased QRS vm, respectively. Conclusions Our findings highlight that cumulative risk score derived from ECG may contribute to improve risk stratification in patients with tetralogy of Fallot, in particular QRS fragmentation and QRS vm in association with QRS duration and other traditional risk factors.

A validation study of the European Society of Cardiology guidelines for risk stratification of sudden cardiac death in childhood hypertrophic cardiomyopathy.

AimsSudden cardiac death (SCD) is the most common cause of death in children with hypertrophic cardiomyopathy (HCM). The European Society of Cardiology (ESC) recommends consideration of an implantable cardioverter-defibrillator (ICD) if two or more clinical risk factors (RFs) are present, but this approach to risk stratification has not been formally validated.Methods and resultsFour hundred and eleven paediatric HCM patients were assessed for four clinical RFs in accordance with current ESC recommendations: severe left ventricular hypertrophy, unexplained syncope, non-sustained ventricular tachycardia, and family history of SCD. The primary endpoint was a composite outcome of SCD or an equivalent event (aborted cardiac arrest, appropriate ICD therapy, or sustained ventricular tachycardia), defined as a major arrhythmic cardiac event (MACE). Over a follow-up period of 2890 patient years (median 5.5 years), MACE occurred in 21 patients (7.5%) with 0 RFs, 19 (16.8%) with 1 RFs, and 3 (18.8%) with 2 or more RFs. Corresponding incidence rates were 1.13 [95% confidence interval (CI) 0.7–1.73], 2.07 (95% CI 1.25–3.23), and 2.52 (95% CI 0.53–7.35) per 100 patient years at risk. Patients with two or more RFs did not have a higher incidence of MACE (log-rank test P = 0.34), with a positive and negative predictive value of 19% and 90%, respectively. The C-statistic was 0.62 (95% CI 0.52–0.72) at 5 years.ConclusionsThe incidence of MACE is higher for patients with increasing numbers of clinical RFs. However, the current ESC guidelines have a low ability to discriminate between high- and low-risk individuals.

Presence of fragmented QRS may be associated with complex ventricular arrhythmias in patients with essential hypertension

BackgroundVentricular arrhythmias (VAs) are frequent in hypertensive patients. Myocardial fibrosis is one of the components of left ventricular hypertrophy secondary to hypertension. Fragmented QRS (fQRS) on electrocardiography (ECG) has been shown to be a marker of myocardial fibrosis. In this study, we aimed to investigate the association between fQRS and complex VAs in patients with essential hypertension. MethodsTwo hundreds consecutive patients who were diagnosed with hypertension were included in the study. The control group consisted of 153 age and sex matched healthy individuals. ECG and transthoracic echocardiography were performed to all patients. fQRS was defined as additional R' wave or notching/splitting of S wave in two contiguous ECG leads. All patients underwent 24-hour Holter monitoring and VAs were classified using Lown's scoring system. Lown class ≥3 VAs were considered as complex VAs. ResultsThere was no significant difference with respect to age (52 ± 8 vs 52 ± 6 years, p = 0.836) and gender distribution (female: 64% vs 63%, p = 0.907) between the groups. As compared to the healthy individuals, prevalence of fQRS (67% vs 9.2%, p < 0.001) and complex VAs (19% vs 0%, p < 0.001) were significantly higher in patients with hypertension. Furthermore, complex VAs (25.4% vs 6.1%, p = 0.001) were significantly higher in hypertensive patients with fQRS. In multiple logistic regression analysis, left ventricular ejection fraction (OR: 1.11, 95%CI: 1.025 to 1.183; p = 0.006), left ventricular mass index (OR: 1.04, 95%CI: 1.021 to 1.107; p = 0.001) and presence of fQRS (OR: 5.605, 95%CI: 1.427 to 22.019; p = 0.014) were independent predictors for complex VAs. ConclusionThe presence of fQRS may be associated with complex VAs in patients with essential hypertension. Therefore, fQRS may be used in risk stratification of complex VAs and sudden cardiac death especially in hypertensive patients with left ventricular hypertrophy.

Does the ‘Normal’ QRS (duration

Ventricular arrhythmias (VAs) are frequent in hypertensive patients. Myocardial fibrosis is one of the components of left ventricular hypertrophy secondary to hypertension. Fragmented QRS (fQRS) on electrocardiography (ECG) has been shown to be a marker of myocardial fibrosis. In this study, we aimed to investigate the association between fQRS and complex VAs in patients with essential hypertension.Two hundreds consecutive patients who were diagnosed with hypertension were included in the study. The control group consisted of 153 age and sex matched healthy individuals. ECG and transthoracic echocardiography were performed to all patients. fQRS was defined as additional R' wave or notching/splitting of S wave in two contiguous ECG leads. All patients underwent 24-hour Holter monitoring and VAs were classified using Lown's scoring system. Lown class ≥3 VAs were considered as complex VAs.There was no significant difference with respect to age (52 ± 8 vs 52 ± 6 years, p = 0.836) and gender distribution (female: 64% vs 63%, p = 0.907) between the groups. As compared to the healthy individuals, prevalence of fQRS (67% vs 9.2%, p < 0.001) and complex VAs (19% vs 0%, p < 0.001) were significantly higher in patients with hypertension. Furthermore, complex VAs (25.4% vs 6.1%, p = 0.001) were significantly higher in hypertensive patients with fQRS. In multiple logistic regression analysis, left ventricular ejection fraction (OR: 1.11, 95%CI: 1.025 to 1.183; p = 0.006), left ventricular mass index (OR: 1.04, 95%CI: 1.021 to 1.107; p = 0.001) and presence of fQRS (OR: 5.605, 95%CI: 1.427 to 22.019; p = 0.014) were independent predictors for complex VAs.The presence of fQRS may be associated with complex VAs in patients with essential hypertension. Therefore, fQRS may be used in risk stratification of complex VAs and sudden cardiac death especially in hypertensive patients with left ventricular hypertrophy.

A Low-cost Version of the Fridericia´s Formula for QT Correction

Ventricular arrhythmias (VAs) are frequent in hypertensive patients. Myocardial fibrosis is one of the components of left ventricular hypertrophy secondary to hypertension. Fragmented QRS (fQRS) on electrocardiography (ECG) has been shown to be a marker of myocardial fibrosis. In this study, we aimed to investigate the association between fQRS and complex VAs in patients with essential hypertension.Two hundreds consecutive patients who were diagnosed with hypertension were included in the study. The control group consisted of 153 age and sex matched healthy individuals. ECG and transthoracic echocardiography were performed to all patients. fQRS was defined as additional R' wave or notching/splitting of S wave in two contiguous ECG leads. All patients underwent 24-hour Holter monitoring and VAs were classified using Lown's scoring system. Lown class ≥3 VAs were considered as complex VAs.There was no significant difference with respect to age (52 ± 8 vs 52 ± 6 years, p = 0.836) and gender distribution (female: 64% vs 63%, p = 0.907) between the groups. As compared to the healthy individuals, prevalence of fQRS (67% vs 9.2%, p < 0.001) and complex VAs (19% vs 0%, p < 0.001) were significantly higher in patients with hypertension. Furthermore, complex VAs (25.4% vs 6.1%, p = 0.001) were significantly higher in hypertensive patients with fQRS. In multiple logistic regression analysis, left ventricular ejection fraction (OR: 1.11, 95%CI: 1.025 to 1.183; p = 0.006), left ventricular mass index (OR: 1.04, 95%CI: 1.021 to 1.107; p = 0.001) and presence of fQRS (OR: 5.605, 95%CI: 1.427 to 22.019; p = 0.014) were independent predictors for complex VAs.The presence of fQRS may be associated with complex VAs in patients with essential hypertension. Therefore, fQRS may be used in risk stratification of complex VAs and sudden cardiac death especially in hypertensive patients with left ventricular hypertrophy.

Local Activation Delay Exacerbates Local J-ST Elevation in the Epicardium: Electrophysiological Substrate in Brugada Syndrome

Ventricular arrhythmias (VAs) are frequent in hypertensive patients. Myocardial fibrosis is one of the components of left ventricular hypertrophy secondary to hypertension. Fragmented QRS (fQRS) on electrocardiography (ECG) has been shown to be a marker of myocardial fibrosis. In this study, we aimed to investigate the association between fQRS and complex VAs in patients with essential hypertension.Two hundreds consecutive patients who were diagnosed with hypertension were included in the study. The control group consisted of 153 age and sex matched healthy individuals. ECG and transthoracic echocardiography were performed to all patients. fQRS was defined as additional R' wave or notching/splitting of S wave in two contiguous ECG leads. All patients underwent 24-hour Holter monitoring and VAs were classified using Lown's scoring system. Lown class ≥3 VAs were considered as complex VAs.There was no significant difference with respect to age (52 ± 8 vs 52 ± 6 years, p = 0.836) and gender distribution (female: 64% vs 63%, p = 0.907) between the groups. As compared to the healthy individuals, prevalence of fQRS (67% vs 9.2%, p < 0.001) and complex VAs (19% vs 0%, p < 0.001) were significantly higher in patients with hypertension. Furthermore, complex VAs (25.4% vs 6.1%, p = 0.001) were significantly higher in hypertensive patients with fQRS. In multiple logistic regression analysis, left ventricular ejection fraction (OR: 1.11, 95%CI: 1.025 to 1.183; p = 0.006), left ventricular mass index (OR: 1.04, 95%CI: 1.021 to 1.107; p = 0.001) and presence of fQRS (OR: 5.605, 95%CI: 1.427 to 22.019; p = 0.014) were independent predictors for complex VAs.The presence of fQRS may be associated with complex VAs in patients with essential hypertension. Therefore, fQRS may be used in risk stratification of complex VAs and sudden cardiac death especially in hypertensive patients with left ventricular hypertrophy.

Identifying Ventricular Arrhythmias and Their Predictors by Applying Machine Learning Methods to Electronic Health Records in Patients With Hypertrophic Cardiomyopathy (HCM-VAr-Risk Model)

Clinical risk stratification for sudden cardiac death (SCD) in hypertrophic cardiomyopathy (HC) employs rules derived from American College of Cardiology Foundation/American Heart Association (ACCF/AHA) guidelines or the HCM Risk-SCD model (C-index ∼0.69), which utilize a few clinical variables. We assessed whether data-driven machine learning methods that consider a wider range of variables can effectively identify HC patients with ventricular arrhythmias (VAr) that lead to SCD. We scanned the electronic health records of 711 HC patients for sustained ventricular tachycardia or ventricular fibrillation. Patients with ventricular tachycardia or ventricular fibrillation (n = 61) were tagged as VAr cases and the remaining (n = 650) as non-VAr. The 2-sample ttest and information gain criterion were used to identify the most informative clinical variables that distinguish VAr from non-VAr; patient records were reduced to include only these variables. Data imbalance stemming from low number of VAr cases was addressed by applying a combination of over- and undersampling strategies. We trained and tested multiple classifiers under this sampling approach, showing effective classification. We evaluated 93 clinical variables, of which 22 proved predictive of VAr. The ensemble of logistic regression and naïve Bayes classifiers, trained based on these 22 variables and corrected for data imbalance, was most effective in separating VAr from non-VAr cases (sensitivity = 0.73, specificity = 0.76, C-index = 0.83). Our method (HCM-VAr-Risk Model) identified 12 new predictors of VAr, in addition to 10 established SCD predictors. In conclusion, this is the first application of machine learning for identifying HC patients with VAr, using clinical attributes. Our model demonstrates good performance (C-index) compared with currently employed SCD prediction algorithms, while addressing imbalance inherent in clinical data.

Radionuclide Imaging in Chagas Cardiomyopathy

To review the contributions of radionuclide imaging to understanding the manifestations and pathophysiology of chronic Chagas cardiomyopathy (CCC). Experimental studies using high-resolution SPECT myocardial perfusion imaging (MPI) show that myocardial perfusion derangement that corresponds to dysfunctional, viable myocardium is closely linked to inflammation and precedes LV regional systolic dysfunction. Clinical studies show that microvascular ischemia is strictly related to the areas of cardiac sympathetic denervation, assessed by 123I-MIBG imaging, which correlates with severe ventricular arrhythmia incidence. Initial case reports suggest that 18F-FDG-PET imaging is a promising, non-invasive detection method for myocardial inflammation. Available evidence indicates that microvascular ischemia participates in the mechanisms causing myocardial injury in CCC, with potential implication for monitoring subclinical disease progression. Moreover, MIBG imaging is a promising tool for risk stratification of sudden death. Preliminary clinical experience suggests a role for 18F-FDG-PET in detection of inflammation in CCC.

СТРАТИФИКАЦИЯ РИСКА ВНЕЗАПНОЙ СЕРДЕЧНОЙ СМЕРТИ ПРИ СИНДРОМЕ РАННЕЙ РЕПОЛЯРИЗАЦИИ ЖЕЛУДОЧКОВ

The article describes approaches to risk stratification of sudden cardiac death in early ventricular repolarization syndrome, as one of the variants of J-wave syndrome, on the basis of clinical, anamnestic and electrocardiographic criteria. The characteristics of malignant variants of electrocardiographic pattern of early ventricular repolarization as well as prevention strategies of sudden cardiac death are presented.