Arrhythmic Events In Patients Research Articles

High Signal Intensity on T2-Weighted Cardiovascular Magnetic Resonance Imaging Predicts Life-Threatening Arrhythmic Events in Hypertrophic Cardiomyopathy Patients.

The prognostic value of high signal intensity on T2-weighted cardiovascular magnetic resonance imaging (T2 high signal) in hypertrophic cardiomyopathy (HCM) patients in a single-center cohort was investigated.Methods and Results:A total of 237 HCM patients (median age, 62 years; 143 male) underwent T2-weighted, cine and late gadolinium enhancement (LGE) imaging, and were followed (median duration, 3.4 years) for life-threatening arrhythmic events. The clinical and magnetic resonance imaging characteristics were extracted, and predictors of life-threatening arrhythmic events were assessed on multivariate analysis. LGE was present in 180 patients (75.9%). Median LGE score was 3 in a left ventricle 17-segment model. T2 high signal was present in 49 patients (20.7%). The annual events rate was significantly higher in patients with extensive LGE (score ≥4) than in those without (3.0%/year vs. 0.5%/year, P=0.011). On multivariate analysis, extensive LGE (hazard ratio, 5.650; 95% CI: 1.263-25.000, P=0.024) as an independent predictor for life-threatening arrhythmic events. In patients with extensive LGE, the annual events rate was significantly higher in patients with T2 high signal than in those without (5.8%/year vs. 0.9%/year, P=0.008). Extensive LGE was an independent predictor of life-threatening arrhythmic events in HCM patients. Furthermore, T2 high signal is useful for the risk stratification of serious arrhythmic events in patients with extensive LGE.

Isolated Late Activation Detected by Magnetocardiography Predicts Future Lethal Ventricular Arrhythmic Events in Patients With Arrhythmogenic Right Ventricular Cardiomyopathy

Risk stratification of ventricular arrhythmias is vital to the optimal management in patients with arrhythmogenic right ventricular cardiomyopathy (ARVC). We hypothesized that 64-channel magnetocardiography (MCG) would be useful to detect isolated late activation (ILA) by overcoming the limitations of conventional noninvasive predictors of ventricular tachyarrhythmias, including epsilon waves, late potential (LP), and right ventricular ejection fraction (RVEF), in ARVC patients.Methods and Results:We evaluated ILA on MCG, defined as discrete activations re-emerging after the decay of main RV activation (%magnitude >5%), and conventional noninvasive predictors of ventricular tachyarrhythmias (epsilon waves, LP, and RVEF) in 40 patients with ARVC. ILA was noted in 24 (60%) patients. Most ILAs were found in RV lateral or inferior areas (17/24, 71%). We defined "delayed ILA" as ILA in which the conduction delay exceeded its median (50 ms). During a median follow-up of 42.5 months, major arrhythmic events (MAEs: 1 sudden cardiac death, 3 sustained ventricular tachycardias, and 4 appropriate implantable cardioverter defibrillator discharges) occurred more frequently in patients with delayed ILA (6/12) than in those without (2/28; log-rank: P=0.004). Cox regression analysis identified delayed ILA as the only independent predictor of MAEs (hazard ratio 7.63, 95% confidence interval 1.72-52.6, P=0.007), and other noninvasive parameters were not significant predictors. MCG is useful to identify ARVC patients at high risk of future lethal ventricular arrhythmias.

Refractory ventricular fibrillations after surgical repair of atrial septal defects in a patient with CACNA1C gene mutation - case report

BackgroundCongenital long QT syndrome (LQTS) can cause ventricular arrhythmic events with syncope and sudden death resulting from malignant torsades de pointes (TdP) followed by ventricular fibrillations (VFs). However, the syndrome is often overlooked prior to the development of arrhythmic events in patients with congenital heart diseases demonstrating right bundle branch block on electrocardiogram (ECG). We present a case of an adult patient with congenital heart disease who developed VFs postoperatively, potentially due to his mutation in a LQTS related gene, which was not identified on preoperative assessment due to incomplete evaluation of his family history.Case presentationA 64-year-old man was diagnosed as having multiple atrial septal defects. He presented with no symptoms of heart failure. His preoperative ECG showed complete right bundle branch block (CRBBB) with a corrected QT interval time of 478 ms. He underwent open-heart surgery to close the defects through median sternotomy access. Three hours after the operation, he developed multiple events of TdP and VFs in the intensive care unit. Cardiopulmonary resuscitation and multiple cardioversions were attempted for his repetitive TdP and VFs. He eventually reverted to sinus rhythm, and intravenous beta-blocker was administered to maintain the sinus rhythm. After this event, his family history was reviewed, and it was confirmed that his daughter and grandson had a medical history of arrhythmia. A genetic test confirmed that he had a missense mutation in CACNA1C, p.K1580 T, which is the cause for type 8.ConclusionsThis case highlights the importance of paying attention to other ECG findings in patients with CRBBB, which can mask prolonged QT intervals.

A lower eicosapentaenoic acid/arachidonic acid ratio is associated with in-hospital fatal arrhythmic events in patients with acute myocardial infarction: a J-MINUET substudy.

The ratio of serum eicosapentaenoic acid (EPA) to arachidonic acid (AA) is significantly associated with long-term clinical outcomes in patients with acute myocardial infarction (AMI). However, it has not been conclusively demonstrated that higher serum EPA/AA ratio fares better clinical outcomes in the early phase of AMI. The Japanese registry of acute Myocardial INfarction diagnosed by Universal dEfiniTion (J-MINUET) is a prospective multicenter registry conducted in 28 Japanese medical institutions between July 2012 and March 2014. We enrolled 3,283 consecutive AMI patients who were admitted to participating institutions within 48h of symptom onset. A serum EPA/AA ratio was available for 629 of these patients. The endpoints were in-hospital mortality and major adverse cardiac events (MACE), defined as a composite of all cause death, cardiac failure, ventricular tachycardia (VT) and/or ventricular fibrillation (VF) and bleeding during hospitalization. Although similar rates of in-hospital mortality, cardiac failure, bleeding, and MACE were found in the lower serum EPA/AA group and higher serum EPA/AA group, the incidence of VT/VF during hospitalization was significantly higher in the low ratio group (p=0.008). Receiver operating characteristic curve analysis showed that an EPA/AA ratio <0.35 could predict the incidence of VT/VF with 100% sensitivity and 64.0% specificity. A lower serum EPA/AA ratio was associated with a higher frequency of fatal arrhythmic events in the early phase of AMI.

Tpeak-Tend dispersion as a predictor for malignant arrhythmia events in patients with vasospastic angina

BackgroundTpeak-Tend interval (Tp-e interval) in electrocardiogram (ECG) has been reported to predict malignant arrhythmia events (MAE) in ST-segment elevation myocardial infarction and ion channelopathy. Tp-e interval and other ECG parameters as predictors for MAE was evaluated in patients with vasospastic angina (VA). Methods and resultsSixty-two patients with VA (Non-MAE group) and 20 patients with VA complicated by MAE (MAE group) were enrolled in our Division of Cardiology between January 2010 and December 2015. Continuous variables were analyzed by t-test and categorical variables by Chi-square analysis. Patients with MAE showed greater QTc (corrected QT interval) dispersion (P=0.005), Tp-ec (corrected Tp-e) interval (P=0.001), Tp-ec dispersion (P<0.001) and Tp-e/QT ratio (P<0.001) than those in non-MAE groups when ST-segment elevated. After elevated ST-segment returned, there were no significant differences in these ECG parameters between two groups (All P>0.05). At univariate binary logistic regression analysis QTc dispersion (odds ratio(OR)=1.133; P=0.013), Tp-ec (OR=1.058; P=0.003), Tp-e/QT (OR=1.403; P=0.001), and Tp-ec dispersion (OR=1.497; P=0.004) were significantly associated with MAE. At multivariable logistic regression analysis, Tp-ec dispersion remained a predictor of MAE. Receiver operating characteristic (ROC) curve analysis showed that only AUC (Area under curve) of Tp-ec dispersion had significant difference with those in QTc dispersion (P<0.001), Tp-ec (P=0.003), and Tp-e/QT ratio (P=0.012), respectively. ConclusionsQTc dispersion, Tp-ec, Tp-e/QT and Tp-ec dispersion were significantly increased in VA patients with MAE than those without MAE when coronary spasm was onset. Prolonged Tp-ec dispersion was the best discriminators and a strong independent predictor of MAE in VA patients.

Meta-analysis of Fragmented QRS as an Electrocardiographic Predictor for Arrhythmic Events in Patients with Brugada Syndrome.

Fragmented QRS (fQRS) is an electrocardiographic marker related to ventricular fibrillation (VF) and sudden cardiac death (SCD) in various clinical settings. Current data regarding the prognostic significance of fQRS in Brugada syndrome (BrS) are contradictory. This meta-analysis aimed to evaluate the presence of fQRS as a risk stratification tool in BrS. Electronic databases (PubMed, EMBASE, and Cochrane Library) were searched until May 2016. Eight observational studies accumulating data on 1,637 BrS patients (mean age: 47 ± 11 years) were included in this meta-analysis. The mean follow-up duration ranged from 21 to 96 months. fQRS was found to be an independent predictor of future arrhythmic events in BrS (RR:3.88, 95% CI 2.26 to 6.65, p < 0.00001) with moderate heterogeneity (I2 = 54%, P = 0.03). When analyzing VF as independent end-point, the RR for VF was 3.61, and its 95% CI was 2.11 to 6.18, p < 0.00001. This meta-analysis showed that BrS patients with fQRS are at high risk for future arrhythmic events. The presence of fQRS warrants prospective evaluation as valid arrhythmogenic risk marker in BrS.

P6395Short-term prevalence of fatal ventricular arrhythmic events in patients with newly diagnosed reduced left ventricular ejection fraction

P6395Short-term prevalence of fatal ventricular arrhythmic events in patients with newly diagnosed reduced left ventricular ejection fraction

Role of Electrocardiographic Tpeak-Tend for the Prediction of Ventricular Arrhythmic Events in the Brugada Syndrome

Some previous studies have proposed the electrocardiographic Tpeak-Tend (TpTe) as a possible predictor of ventricular arrhythmic events in patients with Brugada syndrome (BrS). We sought to analyze the association between the parameters of repolarization dispersion (TpTe, TpTe/QT, TpTe dispersion, QTc, and QTd) and ventricular fibrillation/sudden cardiac death in a large cohort of patients with type 1 BrS. A total of 448 consecutive patients with BrS (men 61%, age 45 ± 16 years) with spontaneous (n = 96, 21%) or drug-induced (n = 352, 79%) type 1 electrocardiogram were retrospectively included. At the time of the diagnosis or during a mean follow-up of 93 ± 47 months (median 88 months), 43 patients (9%) documented ventricular arrhythmias. No significant difference was observed in TpTe, TpTe/QT, maximum TpTe, and TpTe dispersion between asymptomatic patients and those with syncope and malignant arrhythmias. TpTe/QT ratio did not also significantly differ between patients with ventricular fibrillation/sudden cardiac death and those asymptomatic ones. In conclusion, TpTe was not significantly prolonged in those patients with type 1 BrS presenting with unexplained syncope or malignant arrhythmic events during follow-up.

Predictors of future arrhythmic events in patients with unexplained syncope

Aims: The purpose of this study was to examine the usefulness of implantable loop recorders (ILRs) for symptom–rhythm correlation and to identify predictors of future arrhythmic events.Patients and methods: In our dual-centre study, we analysed ILR data of 189 patients (mean age 67.4 ± 15.2 years, 114 male) with unexplained syncope (single syncope 21 patients, recurrent 168 patients, traumatic injury 43 patients). Patients had severe comorbidities such as hypertension (n = 127), coronary artery disease (n = 31), diabetes mellitus (n = 33) and chronic renal insufficiency (n = 18). The median ILR usage was 29 months (M), with a range between 1 and 46 M.Results: Forty-nine (26%) patients experienced syncope during the study, with a median of 8 M to first recurrence of syncope. In 43 patients, pacemaker implantation was performed because of sinus node disease (n = 29), high-degree AV-block (n = 6) or atrial fibrillation with slow ventricular rate (n = 8). In five patients, an ICD was implanted because of documented ventricular tachycardia (n = 4) or left ventricular ejection fraction <35% (n = 1). One patient received ablation of the cavotricuspid isthmus because of documented atrial flutter. Concerning the clinical course, in five patients explantation of the ILR was necessary due to pocket infection. Three patients died due to non-cardiac causes. Logistic regression analysis revealed that older patients had a significantly higher risk for future arrhythmic events (OR 1.3, p = .039).Conclusions: ILR monitoring is effective in indicating causes of unexplained syncope by providing symptom–rhythm associations. Only age was a predictor of future arrhythmic events. The mortality in patients with unexplained syncope was very low.

Automated Quantification of Low-Amplitude Abnormal QRS Peaks From High-Resolution ECG Recordings Predicts Arrhythmic Events in Patients With Cardiomyopathy.

Cardiomyopathy patients are at risk of sudden death, typically from scar-related abnormalities of electrical activation that promote ventricular tachyarrhythmias. Abnormal intra-QRS peaks may provide a measure of altered activation. We hypothesized that quantification of such QRS peaks (QRSp) in high-resolution ECGs would predict arrhythmic events in implantable cardioverter-defibrillator (ICD)-eligible cardiomyopathy patients. Ninety-nine patients with ischemic or non-ischemic dilated cardiomyopathy undergoing prophylactic ICD implantation were prospectively enrolled (age 62±11 years, left ventricular ejection fraction 27±7%). High-resolution (1024 Hz) digital 12-lead ECGs were recorded during intrinsic rhythm. QRSp was quantified for each precordial lead as the total number of low-amplitude deflections that deviated from their respective naive QRS template. The primary end point of arrhythmic events was defined as appropriate ICD therapy or sustained ventricular tachyarrhythmias. After a median follow-up of 24 (15-43) months, 20 (20%) patients had arrhythmic events. Both QRSp and QRS duration were greater in those with arrhythmic events (both P<0.001) and this was consistent for QRSp for both cardiomyopathy types. In a multivariable Cox regression model that included age, left ventricular ejection fraction, QRS duration, and QRSp, only QRSp was an independent predictor of arrhythmic events (hazard ratio, 2.1; P<0.001). Receiver operating characteristic analysis revealed that a QRSp ≥2.25 identified arrhythmic events with greater sensitivity (100% versus 70%, P<0.05) and negative predictive value (100% versus 89%, P<0.05) than QRS duration ≥120 ms. QRSp measured from high-resolution digital 12-lead ECGs independently predicts ventricular tachyarrhythmias in ICD-eligible cardiomyopathy patients. This novel QRS morphology index has the potential to improve sudden death risk stratification and patient selection for prophylactic ICD therapy.

Assessment of 123I-mIBG and 99mTc-tetrofosmin single-photon emission computed tomographic images for the prediction of arrhythmic events in patients with ischemic heart failure: Intermediate severity innervation defects are associated with higher arrhythmic risk

Rationale123I-mIBG planar image heart-to-mediastinum ratios effectively risk-stratify heart failure (HF) patients. The value of single-photon emission computed tomographic (SPECT) imaging for identifying increased risk of ventricular arrhythmias is less clear. This study sought to determine if findings from simultaneous interpretation of 123I-mIBG and 99mTc-tetrofosmin SPECT are predictive of arrhythmic events (ArEs). Methods123I-mIBG SPECT images from 622 patients with ischemic HF were presented in standard displays alongside 99mTc-tetrofosmin images. Consensus interpretations using a 17-segment model produced summed scores. Cox proportional hazards analyses related findings to adjudicated ArEs over 2 years. Results471 patients had images adequate for total 17-segment scoring. There were 48 ArEs (10.2%). Neither 123I-mIBG nor 99mTc-tetrofosmin SPECT summed scores were univariate predictors. On multivariate proportional hazards analysis, the 123I-mIBG SPECT score was independently predictive of ArEs (HR: 0.975, 95% CI 0.951-0.999, P = 0.042), but HR<1 indicated that risk decreased with increasing score. This occurred because patients with intermediately abnormal SPECT studies had a higher likelihood of ArEs compared to patients with extensive abnormalities. ConclusionsThe presumption of a monotonic increase in ArE risk with increasing summed 123I-mIBG SPECT score may not be correct as ischemic HF patients with abnormalities of intermediate extent appear at highest risk.

Atrial fibrillation in hypertrophic cardiomyopathy: A turning point towards increased morbidity and mortality

BackgroundAtrial fibrillation (AF) is the most common arrhythmic event in patients with hypertrophic cardiomyopathy (HCM). The aim of this study was to identify the clinical impact and prognostic significance of AF on a large cohort of patients with HCM. MethodsEchocardiographic and clinical correlates, risk factors for AF and thromboembolic stroke and the prognostic significance of AF were evaluated in 509 patients with an established diagnosis of HCM. ResultsA total of 119 patients (23.4%) were diagnosed with AF during the index evaluation visit. AF patients had a higher prevalence of stroke and presented with worse functional impairment. Left atrial diameter (LA size) was a common independent predictor of the arrhythmia (OR: 2.2, 95% CI 1.6-3.3) and thromboembolic stroke (OR: 1.6, 95% CI 1.01-2.40). AF was an important risk factor for overall mortality (HR=3.4, 95% CI: 1.7-6.5), HCM-related mortality (HR=3.9, 95% CI: 1.8-8.2) and heart failure-related mortality (HR=6.0, 95% CI: 2.0-17.9), even after adjusting for statistically significant clinical and demographic risk factors. However, AF did not affect the risk for sudden death. ConclusionsLA size is an independent predictor of both AF and thromboembolic stroke. Moreover, patients with AF, regardless of type, have significantly higher mortality rates than patients without AF.

Fragmented QRS Is a Novel Risk Factor for Ventricular Arrhythmic Events After Receiving Cardiac Resynchronization Therapy in Nonischemic Cardiomyopathy.

A fragmented QRS (fQRS) is reported to be associated with a poor prognosis or sudden cardiac death (SCD) in patients with Brugada syndrome or ischemic heart disease. However, no studies have clarified the impact of the presence of an fQRS on SCD or ventricular arrhythmic events in patients receiving cardiac resynchronization therapy (CRT). This study aimed to clarify this point in patients with nonischemic cardiomyopathy. This study included 137 heart failure patients with nonischemic cardiomyopathy who received CRT (NYHA functional class: II/III/IV = 25/84/28). The 12-lead ECGs before and after CRT were analyzed. The presence of an fQRS was decided in accordance with the definition in previous papers. Before the CRT, an fQRS was observed in 67 patients (fQRS-pre; 49%). However, it was masked in 35 (52% of fQRS-pre) patients after the CRT. Inversely, in 70 patients in whom an fQRS was absent before the CRT, it appeared after the CRT in 15 (21%) patients. As a result, 47 patients (34%) had an fQRS after the CRT (fQRS-post), and it was less than that before the CRT (P = 0.014). During 18 months of follow-up, SCD or ventricular arrhythmic events were observed more frequently in patients with an fQRS-post than in those without (36.2% vs. 3.3%, P < 0.001). A Cox regression analysis revealed that an fQRS-post was significantly associated with those events (hazard ratio = 9.18; 95% confidence interval = 2.45-34.48, P = 0.001). In patients with nonischemic cardiomyopathy who received CRT, an fQRS-post was independently associated with SCD or ventricular arrhythmic events.

A meta-analysis on the prognostic significance of inferolateral early repolarization pattern in Brugada syndrome.

The early repolarization (ER) pattern has been linked to an increased risk for arrhythmic death in various clinical settings. There are limited and conflicting data regarding the prognostic significance of ER pattern in Brugada syndrome (BS). The aim of this meta-analysis was to provide a detailed analysis of the currently available studies regarding the arrhythmic risk in patients with BS and ER pattern. Current databases were searched until May 2015. A random-effect meta-analysis of the effect of ER pattern on the incidence of arrhythmic events in patients with BS was performed. Five studies were included comprising a total of 1375 patients with BS. An ER pattern was reported in 177 patients (12.8%). During follow-up (44.9-93 months), 143 patients (10.4%) suffered an arrhythmic event. Overall, BS patients with ER pattern displayed an increased risk of arrhythmic events compared to patients without ER (OR 3.29, 95% CI: 2.06 to 5.26, P < 0.00001; Heterogeneity: P = 0.11, I2 = 48%). Three studies provided data regarding ER pattern location. Inferior, lateral, or inferolateral ER pattern location was observed in 20.3%, 32.2%, and 48%, respectively. An inferolateral ER location conferred the higher arrhythmic risk (OR 4.87, 95% CI: 2.64 to 9.01, P< 0.00001; Heterogeneity: P = 0.85, I2 = 0%). This meta-analysis suggests that the ER pattern is associated with a high risk of arrhythmic events in patients with BS. In particular, BS patients with inferolateral ER (global ER pattern) displayed the highest arrhythmic risk.

Usefulness of right ventricular and right atrial two-dimensional speckle tracking strain to predict late arrhythmic events in adult patients with repaired Tetralogy of Fallot

ObjectiveTo determine whether right ventricular and/or atrial speckle tracking strain is associated with previous arrhythmic events in patients with repaired tetralogy of Fallot. Methods and ResultsWe studied right ventricular and atrial strain in 100 consecutive patients with repaired tetralogy of Fallot referred for routine echocardiographic evaluation. Patients were divided into two groups, one with previous documentation of arrhythmias (n=26) and one without arrhythmias, in a median follow-up of 22 years. Patients with arrhythmias were older (p<0.001) and had surgical repair at an older age (p=0.001). They also had significantly reduced right ventricular strain (-14.7±5.5 vs. -16.9±4.0%, p=0.029) and right atrial strain (19.1±7.7% vs. 25.8±11.4%, p=0.001). Neither right ventricular nor right atrial strain were independent predictors of the presence of a history of documented arrhythmias, which was associated with age at correction and with the presence of residual defects. In a subanalysis after excluding 23 patients who had had more than one corrective surgery, right ventricular strain was an independent predictor of the presence of previous arrhythmic events (OR 1.19, 95% CI 1.02-1.38, p=0.025). Right atrial strain was also an independent predictor after adjustment (OR 0.93, 95% CI 0.87-0.99, p=0.029). The ideal cut-off for right ventricular strain was -15.3% and for right atrial strain 23.0%. ConclusionsCompared with conventional echocardiographic parameters, strain measures of the right heart are associated with the presence of arrhythmic events, and may be useful for risk stratification of patients with repaired tetralogy of Fallot, although a prospective study is required.

Assessment of repolarization abnormalities in baseline electrocardiograms of patients with myocarditis

Background/aim: Myocarditis in the acute phase usually presents with sinus tachycardia but many other arrhythmias might be seen as well. In this study we aimed to investigate repolarization abnormalities in baseline ECG of patients with myocarditis for the first time.Materials and methods: Thirty patients diagnosed with myocarditis and 25 healthy age-matched controls were included. Two different cardiologists measured corrected QT (QTc), QT dispersion (QTd), QT peak (QTp), T wave peak to T wave end (TpTe), TpTe/QT ratio, and TpTe/QTc ratio in 12-lead ECG.Results: When compared with the control group, QTp (P: 0.021), QT (P: 0.003), TpTe (P < 0.001), TpTe/QTc ratio (P < 0.001), and TpTe/QT ratio (P: 0.005) were significantly higher in patients with myocarditis. A comparison of receiver operating characteristic (ROC) curves was conducted using the Hanley and McNeil method. The area under the curve (AUC) of the electrocardiographic characteristics QT (AUC: 0.736; 95% CI [0.600-0.846]), QTP (AUC: 0.680; 95% CI [0.540-0.799]), and TpTe (AUC: 0.771; 95% CI [0.638-873]) and TpTe/QTc (AUC: 0.774; 95% CI [0.641-0.876]) and TpTe/QT (AUC: 0.726; 95% CI [0.589-0.838]) in myocarditis were not significantly different from each other but all of them were different from 0.5.Conclusion: Baseline ECGs of patients with myocarditis were associated with repolarization abnormalities. These novel findings may be one of the reasons underlying arrhythmic events in patients with myocarditis.

Right Ventricular Ejection Fraction Is Incremental to Left Ventricular Ejection Fraction for the Prediction of Future Arrhythmic Events in Patients With Systolic Dysfunction.

Left ventricular ejection fraction remains the primary risk stratification tool used in the selection of patients for implantable cardioverter defibrillator therapy. However, this solitary marker fails to identify a substantial portion of patients experiencing sudden cardiac arrest. In this study, we examined the incremental value of considering right ventricular ejection fraction for the prediction of future arrhythmic events in patients with systolic dysfunction using the gold standard of cardiovascular magnetic resonance. Three hundred fourteen consecutive patients with ischemic cardiomyopathy or nonischemic dilated cardiomyopathy undergoing cardiovascular magnetic resonance were followed for the primary outcome of sudden cardiac arrest or appropriate implantable cardioverter defibrillator therapy. Blinded quantification of left ventricular and right ventricular (RV) volumes was performed from standard cine imaging. Quantification of fibrosis from late gadolinium enhancement imaging was incrementally performed. RV dysfunction was defined as right ventricular ejection fraction ≤45%. Among all patients (164 ischemic cardiomyopathy, 150 nonischemic dilated cardiomyopathy), the mean left ventricular ejection fraction was 32±12% (range, 6-54%) with mean right ventricular ejection fraction of 48±15% (range, 7-78%). At a median of 773 days, 49 patients (15.6%) experienced the primary outcome (9 sudden cardiac arrest, 40 appropriate implantable cardioverter defibrillator therapies). RV dysfunction was independently predictive of the primary outcome (hazard ratio=2.98; P=0.002). Among those with a left ventricular ejection fraction >35% (N=121; mean left ventricular ejection fraction, 45±6%), RV dysfunction provided an adjusted hazard ratio of 4.2 (P=0.02). RV dysfunction is a strong, independent predictor of arrhythmic events. Among patients with mild to moderate LV dysfunction, a cohort greatly contributing to global sudden cardiac arrest burden, this marker provides robust discrimination of high- versus low-risk subjects.

Predictors of serious arrhythmic events in patients with nonischemic heart failure.

Risk stratification of serious arrhythmic events in patients with nonischemic heart failure (HF), beyond estimates of left ventricular ejection fraction (LVEF), remains an important clinical challenge. This study aims to determine the clinical value of different noninvasive and invasive tests as predictors of serious arrhythmic events in patients with nonischemic HF. A prospective observational study was conducted including 106 nonischemic HF patients who underwent a comprehensive clinical and laboratory evaluation including two-dimensional echocardiography, 24-h Holter monitoring, cardiopulmonary exercise testing (CPX), and an invasive electrophysiological study. The study's primary end-point was either syncope, appropriate therapy by implantable cardioverter-defibrillators, or sudden cardiac death. During a mean follow-up of 704 ± 320days, the primary end-point occurred in 15 patients (14.2%). In multivariable analysis, LV end-diastolic diameter >73mm (hazard ratio [HR] 3.7; p = 0.016), exercise periodic breathing (EPB) on CPX (HR 2.88; p = 0.045), and non-sustained ventricular tachycardia (NSVT) ≥10 beats (HR 8.2; p < 0.01) remained independently associated with serious arrhythmic events. The positive predictive value of the presence of two of these predictors ranged from 44 to 100%. The absence of all three factors (n = 65, 61% of the sample) identified a subset of patients with low risk of future arrhythmic events, with a negative predictive value of 96.9%. In this cohort study of nonischemic HF patients, LV dimension, EPB, and NSVT ≥10 beats were independent predictors of serious arrhythmic events. The presence or absence of these characteristics identified sub-groups of high and low risk of serious arrhythmic events, respectively.

Usefulness of right ventricular and right atrial two-dimensional speckle tracking strain to predict late arrhythmic events in adult patients with repaired Tetralogy of Fallot

ObjectiveTo determine whether right ventricular and/or atrial speckle tracking strain is associated with previous arrhythmic events in patients with repaired tetralogy of Fallot. Methods and ResultsWe studied right ventricular and atrial strain in 100 consecutive patients with repaired tetralogy of Fallot referred for routine echocardiographic evaluation. Patients were divided into two groups, one with previous documentation of arrhythmias (n=26) and one without arrhythmias, in a median follow-up of 22 years. Patients with arrhythmias were older (p<0.001) and had surgical repair at an older age (p=0.001). They also had significantly reduced right ventricular strain (-14.7±5.5 vs. -16.9±4.0%, p=0.029) and right atrial strain (19.1±7.7% vs. 25.8±11.4%, p=0.001). Neither right ventricular nor right atrial strain were independent predictors of the presence of a history of documented arrhythmias, which was associated with age at correction and with the presence of residual defects. In a subanalysis after excluding 23 patients who had had more than one corrective surgery, right ventricular strain was an independent predictor of the presence of previous arrhythmic events (OR 1.19, 95% CI 1.02-1.38, p=0.025). Right atrial strain was also an independent predictor after adjustment (OR 0.93, 95% CI 0.87-0.99, p=0.029). The ideal cut-off for right ventricular strain was -15.3% and for right atrial strain 23.0%. ConclusionsCompared with conventional echocardiographic parameters, strain measures of the right heart are associated with the presence of arrhythmic events, and may be useful for risk stratification of patients with repaired tetralogy of Fallot, although a prospective study is required.

Combination of ECG and Echocardiography for Identification of Arrhythmic Events in Early ARVC

ObjectivesThe aim of this study was to investigate early markers of arrhythmic events (AEs) and improve risk stratification in early arrhythmogenic right ventricular cardiomyopathy (ARVC). BackgroundAEs are frequent in patients with ARVC, but risk stratification in subjects with early ARVC is challenging. MethodsEarly ARVC disease was defined as possible or borderline ARVC diagnosis according to the ARVC Task Force Criteria 2010. We performed resting and signal averaged electrocardiogram (ECG). Using echocardiography, we assessed right ventricular (RV) outflow tract diameter and right ventricular basal diameter (RV diameter). Global longitudinal strain and mechanical dispersion (MD) from strain echocardiography were assessed in both the right and left ventricle. AEs were defined as documented ventricular tachycardia, cardiac syncope, or aborted cardiac arrest. ResultsOf 162 included subjects with ARVC (41 ± 16 years of age, 47% female), 73 had early ARVC, including mutation positive family members not fulfilling definite ARVC diagnosis. AEs occurred in 15 (21%) subjects with early ARVC. Those with AEs in early disease had larger RV diameter (40 ± 4 mm vs. 37 ± 5 mm), more pronounced RVMD (39 ± 15 ms vs. 26 ± 11 ms), and more pathological signal averaged ECGs compared with those without AEs (all p ≤ 0.05). Adding measurements of RV diameter and RVMD to electrical parameters improved identification of subjects with AEs compared with electrical parameters alone (p = 0.05). ConclusionsECG parameters, RV diameter, and RVMD were markers of previous arrhythmic events in patients with early ARVC. A combination of electrical and echocardiographic parameters improved identification of subjects with AEs in early ARVC disease.