Malignant Arrhythmias In Patients Research Articles

Evaluation of the Risk of Malignant Arrhythmia Through Electrocardiography Parameters in Patients with Urinary Stone Disease

Introduction: With a lifetime frequency of 10-15% and a recurrence rate of up to 50% within 10 years, urinary stone disease is a major cause of comorbidity. Recently, it has become widely recognized that urinary system stone disease is not only limited to kidney stone development but is also linked to cardiovascular disease and various other illnesses. Malignant arrhythmias (sudden cardiac death and ventricular arrhythmias) are consequences of coronary artery disease. Despite numerous studies demonstrating that urinary system stone disease is a risk factor for coronary artery disease, no electrocardiographic parameters have been evaluated in this patient group This prospective observational study aims to assess ventricular repolarization parameters using electrocardiography, which are risk indicators for malignant arrhythmias in patients with urinary stones disease. Materials and Methods The study included patients diagnosed with urinary stone disease and healthy volunteers. All patients underwent 12-lead electrocardiography. The electrocardiographys were evaluated for QTc interval, QTc dispersion, T peak-end interval, and Tp-e/QTc, and compared with the control group. Results: When comparing the QTc interval, QTc dispersion, T peak-end interval, and Tp-e/QTc parameters between the patient and control groups, no statistically significant differences were found. Conclusion: Contrary to existing knowledge, this study found that malignant arrhythmias in patients with urinary stone disease were not significantly different from the normal population.

High-risk phenotypes of arrhythmic mitral valve prolapse: a systematic review and meta-analysis

Background Mitral valve prolapse (MVP) is associated with aggravated risk of ventricular tachycardia (VT), ventricular fibrillation (VF) and sudden cardiac death (SCD). There is a lack of specific guideline recommendation regarding risk stratification and management, despite multiple proposed high-risk phenotypes. We performed systematic review and meta-analysis to evaluate high-risk phenotypes for malignant arrhythmias in patients with MVP. Methods We comprehensively searched the databases of MEDLINE, SCOPUS, and EMBASE from inception to April 2023. Included studies were cohort and case-control comparing between MVP patients with and without VT, VF, cardiac arrest, ICD placement, or SCD. Data from each study were combined using the random-effects. Pooled odds ratios (OR) and 95% confidence intervals (CI) were calculated. Results Nine studies from 1985 to 2023 were included involving 2,279 patients with MVP. We found that T-wave inversion (OR 2.52; 95% CI: 1.90–3.33; p < 0.001), bileaflet involvement (OR 2.28; 95% CI: 1.69–3.09; p < 0.001), late gadolinium enhancement (OR 17.05; 95% CI: 3.41–85.22; p < 0.001), mitral annular disjunction (OR 3.71; 95% CI: 1.63–8.41; p < 0.002), and history of syncope (OR 6.96; 95% CI: 1.05–46.01; p = 0.044), but not female (OR 0.96; 95% CI: 0.46–2.01; p = 0.911), redundant leaflets (OR 4.30; 95% CI: 0.81–22.84; p = 0.087), or moderate-to-severe mitral regurgitation (OR 1.24; 95% CI: 0.65–2.37; p = 0.505), were associated with those events. Conclusion Bileaflet prolapse, T-wave inversion, mitral annular disjunction, late gadolinium enhancement, and history of syncope are high-risk phenotypes among population with MVP. Further research is needed to validate the risk stratification model and justify the role of primary prophylaxis against malignant arrhythmias.

Prognostic factors in young patients with ST-segment elevation myocardial infarction.

The prognostic factors of young patients aged ≤40 years with ST-segment elevation myocardial infarction (STEMI) remain unclear. This study explored risk factors that may affect the 1-year prognosis of young STEMI patients by analyzing patient data of baseline, clinical regimen, and secondary prevention. Baseline and clinical data were collected from 420 STEMI patients aged ≤40 years. One year of follow-up was performed to record and compare the differences in data between patients with and without adverse events. Binary logistic regression analysis with controls for confounding factors was used to evaluate prognosis-related independent factors. The overall incidence of cardiovascular adverse events was 15.95%. Comparison of the subgroups revealed that regardless of adjustment for confounding factors, prognoses of the patients were affected by the following factors: BMI, marital status, serum apolipoprotein(a) (ApoA) levels, number of diseased vessels, treatment regimen, compliance of secondary prevention, improvement of lifestyle, and adjusted comorbidities ( P < 0.05). Independent analysis of adverse events revealed that BMI, number of diseased vessels, and compliance of secondary prevention were independent factors of recurrent acute myocardial infarction in patients. Serum ApoA level, treatment regimen, and compliance of secondary prevention were independent influence factors of heart failure in patients. Marital status and serum ApoA level were independent factors of malignant arrhythmias in patients. BMI, compliance of secondary prevention, and improvement of lifestyle were independent factors of cardiac death in patients. This study determined the influential factors for the prognosis of STEMI patients aged ≤40 years as follows: BMI, marital status, comorbidities, number of diseased vessels, regimen, compliance of secondary prevention, and improvement of lifestyle. The risk of cardiovascular adverse events may be reduced by modulating the influential factors.

Abstract 11364: Risks Factors for Malignant Arrhythmias and Sudden Cardiac Death in Patients With Mitral Valve Prolapse: A Systematic Review and Meta-Analysis

Introduction: Mitral valve prolapse (MVP) is a common valvular disorder affecting approximately 3% of the population. Several risk factors in patients with MVP for malignant arrythmias, including ventricular tachycardia (VT), fibrillation (VF), and sudden cardiac death (SCD), have been proposed. We performed systematic review and meta-analysis to evaluate risk factors for malignant arrhythmias in patients with MVP. Methods: We comprehensively searched the databases of MEDLINE from inception to May 2022. Included studies were published cohorts comparing patients with MVP and malignant arrhythmias or SCD versus MVP without those events. Data from each study were combined using the random-effects model. Pooled odd ratios (OR) and 95% confidence intervals (CI) were calculated. Results: Five studies from 1985 to 2021 were included involving 769 patients with MVP [100 patients with SCD, VF, VT, and/or implantable cardioverter defibrillator (ICD) shocks]. We found that T-wave inversion (pooled OR=3.14, 95%CI: 2.18-4.5, p&lt;0.001), bileaflet (pooled OR=2.37, 95%CI: 1.39-4.04, p=0.002), late gadolinium enhancement (pooled OR=41.8, 95%CI: 10.7-163, p&lt;0.001), mitral annular disjunction (pooled OR=4.8, 95%CI: 2.7-8.4, p&lt;0.001), redundant leaflets (pooled OR=4.6, 95%CI: 1.02-21.0, p=0.048), and history of syncope (pooled OR=2, 95%CI: 1.002-4.02, p=0.049), were associated with malignant arrythmias and SCD. However, female sex (pooled OR=0.83, 95%CI: 0.26 - 2.65, p=0.748) and moderate-to-severe mitral regurgitation (pooled OR=0.85, 95%CI:0.15-4.91, p=0.853) did not increase the risk. Conclusion: T-wave inversion, mitral annular disjunction, late gadolinium enhancement, history of syncope, redundant leaflets and bileaflet prolapse are associated with an increased risk of malignant arrhythmias and SCD in patients with MVP. Further studies are needed to evaluate the role of electrophysiologic study and ICD in this high-risk population.

Long QT syndrome: long story short.

The first report of long QT syndrome (LQTS) dates back to 1856 when Friedrich Ludwig Meissner, a German obstetrician and pediatrician, described a child with deafness, who died while being publicly reprimanded by the schoolteacher.1 It took nearly a century to document the very first electrocardiogram (ECG) of a prolonged QT interval coinciding with deafness and syncope.2 The association between sudden deaths in children with congenital deafness and QT prolongation was brought up by two concurrent publications authored by Anton Jervell with Fred Lange-Nielsen and Samuel A. Levine with Clyde R. Woodworth.3 Following closely, Cesarino Romano et al. and Owen C. Ward described analogous cases in the absence of the auditory component.3 Although Levine and Woodworth’s contribution was never acknowledged, two eponyms, Jervell-Lange-Nielsen and Romano-Ward syndromes, were coined with reference to the congenital form of LQTS with or without deafness, respectively.3 Because syncope and cardiac arrest mainly occurred in stressful situation, sympathetic imbalance was long believed to underlie LQTS.3 It would take 40 years to find the fault in the genes. With the biological Rosetta stone deciphered, research has become ever more crucial to translate gene expression into clinical care for LQTS. While the spectrum of mutations initially encompassed 17 genes reported to be linked to LQTS, 7 are now classified as having disputed evidence.4 Mutations in three genes (KCNQ1, KCNH2, and SCN5A) encoding for cardiac voltage-gated K+ (Kv7.1 or KCNQ1, Kv11.1 or hERG) and Na+ channels (Nav1.5) causing a delay in cardiac repolarization account for the majority of LQTS forms (types 1, 2, and 3, respectively).4 LQTS types 1 and 2 are based on a loss-of-function in Kv7.1 and Kv11.1 channels, respectively, reducing repolarizing outward K+ currents (IKs and IKr). In contrast, LQTS type 3 relates to an increased late Na+ inward current (INa, late) resulting from gain-of-function in Nav1.5 channels.4 While LQTS type 1 typically manifests during childhood, LQTS types 2 and 3 patients become symptomatic after the onset of puberty. Because of the decreased Kv11.1 channel density compared to male as well as the direct inhibitory effect of estrogen, female LQTS type 2 patients are at particular risk for arrhythmias.4 Such cardiac events predominantly occur at rest in LQTS type 3. In contrast, exercise and acoustic/emotional stimuli may trigger malignant arrhythmias in patients with LQTS type 1 and type 2, respectively. Mechanistically, the LQTS heart fails to adapt (impaired repolarization reserve) in response to the excess Ca2+ inflow resulting from sustained adrenergic tone (exercise) or an adrenergic surge (sudden arousal).4 Given the crucial role of sympathetic activity, it is no surprise that beta-blockers are advocated for LQTS patients. Late Na+ channel blockers present a viable adjunct in the pharmacological treatment of LQTS type 3. Left cardiac sympathetic denervation is a surgical antiadrenergic intervention mainly reserved to patients refractory to standard of care. An implantable cardioverter-defibrillator is considered in high-risk and resuscitated patients for the prevention of sudden cardiac death.4 Collectively, none of these treatment modalities addresses the cause of LQTS. In addition, some LQTS patients continue to experience breakthrough cardiac events despite maximal therapy, sparking research efforts in developing new treatment strategies.

Effects of renal denervation therapy on cardiac function and malignant arrhythmia in patients with reduced left ventricular ejection fraction and narrow QRS complexes treated with implantable cardioverter defibrillator.

Objective : The purpose of this study was to explore the effects of renal denervation (RDN) on cardiac function and malignant arrhythmia in patients with reduced left ventricular ejection fraction (HFrEF) and narrow QRS treated with an implantable cardioverter defibrillator (ICD). Methods: A total of 20 eligible HFrEF patients [left ventricular ejection fraction (LVEF) <40%] and narrow QRS complexes (QRS duration <120 ms) were randomized into either the ICD plus RDN group or the ICD only group during 17 April 2014 to 22 November 2016. Clinical data, including clinical characteristics, blood biochemistry, B-type natriuretic peptide, echocardiographic indexes, 6-min walk distance (6MWD), New York Heart Association (NYHA) classification, and count of ICD discharge events before and after the operation were analyzed. Patients were followed up for up to 3 years post ICD or ICD plus RDN. Results: Baseline clinical data were comparable between the two groups. Higher LVEF (%) (mixed model repeated measure, p = 0.0306) (39.50% ± 9.63% vs. 31.20% ± 4.52% at 1 year; 41.57% ± 9.62% vs. 31.40% ± 8.14% at 3 years), systolic blood pressure (p = 0.0356), and longer 6MWD (p < 0.0001) as well as reduction of NYHA classification (p < 0.0001) were evidenced in the ICD plus RDN group compared to ICD only group during follow-up. Patients in the ICD plus RDN group experienced fewer ICD discharge events (2 vs. 40) and decreased diuretic use; rehospitalization rate (30% vs. 100%, p = 0.0031) and cardiogenic mortality rate (0% vs. 50%, p = 0.0325) were also significantly lower in the ICD plus RDN group than in the ICD only group during follow-up. Conclusion: ICD implantation plus RDN could significantly improve cardiac function and cardiac outcome as well as increase exercise capacity compared to ICD only for HFrEF patients with narrow QRS complexes.

Qtc Interval Dispersion in Patients with Acute Str

QT, QTc interval and QTc dispersion express the inhomogeneity of left ventricular repolarization time. Its extension results in an increase of vulnerable period and susceptibility to malignant arrhythmias in patients with cardiovascular and cerebrovascular disease and hence sudden death.

Impact of Medical Castration on Malignant Arrhythmias in Patients With Prostate Cancer.

BackgroundMedical castration, gonadotropin‐releasing hormone agonists, and antiandrogens have been widely applied as a treatment for prostate cancer. Sex steroid hormones influence cardiac ion channels. However, few studies have examined the proarrhythmic properties of medical castration.Methods and ResultsThis study included 149 patients who underwent medical castration using gonadotropin‐releasing hormones with/without antiandrogen for prostate cancer. The changes in the ECG findings during the therapy and associations of the electrocardiographic findings with malignant arrhythmias were studied. The QT and corrected QT (QTc) intervals prolonged during the therapy compared with baseline (QT, 394±32 to 406±39 ms [P<0.001]; QTc, 416±27 to 439±31 ms [P<0.001]). The QTc interval was prolonged in 119 (79.9%) patients during the therapy compared with baseline. In 2 (1.3%) patients who had no structural heart disease, torsade de pointes (TdP) and ventricular fibrillation (VF) occurred ≥6 months after starting the therapy. In patients with TdP/VF, the increase in the QTc interval from the pretreatment value was >80 ms. However, in patients without TdP/VF, the prevalence of an increase in the QTc interval from the pretreatment value of >50 ms was 11%, and an increase in the QTc interval from the pretreatment value >80 ms was found in only 4 (3%) patients.ConclusionsMedical castration prolongs the QT/QTc intervals in most patients with prostate cancer, and it could cause TdP/VFs even in patients with no risk of QT prolongation before the therapy. An increase in the QTc interval from the pretreatment value >50 ms might become a predictor of TdP/VF. Much attention should be paid to the QTc interval throughout all periods of medical castration to prevent malignant arrhythmias.

Lambda-like waveform: A new risk predictor of impending malignant arrhythmias in patients with coronary artery disease

Background: The association between the appearance of a lambda-like waveform and occurrence of malignant arrhythmias during acute myocardial ischemia is unclear in patients with Coronary Artery Disease (CAD). Hypothesis: Lambda-like waveform is a new risk predictor of impending malignant arrhythmias in patients with CAD. Methods: We evaluated electrocardiograms (ECGs) from 8 patients with transient ischemia. The lambda-like pattern was defined as a distinctively notched, giant J wave with a descending ST-segment elevation followed by an alternately negative T wave. The typical pattern was followed by ventricular tachyarrhythmias and/or severe bradyarrhythmias in the CAD group. Results: Lambda-wave patientshad a higher incidence of syncope, CAD, arrhythmia, cardiopulmonary resuscitation, obvious coronary artery stenosis, slower heart rate, and longer PR and QT intervals than the control patients. In addition, more lambda-wave patients took medicine for coronary artery dilatation and had recurrent malignant arrhythmias than the control patients. A difference with respect to the distribution and morphology of ischemic ECG waveforms between the 2 groups was observed. Furthermore, the incidence of severe bradyarrhythmias and/or ventricular tachyarrhythmias was significantly higher in the CAD group than that in the control group. Conclusion: An inferior and lateral lambda-like pattern may predict malignant arrhythmias in patients with CAD. A notched giant J wave may also be a risk factor for impending arrhythmias in inferior and lateral leads. The relevance of this pattern to acute ischemia may be important; however, no risk stratification or management strategies for this pattern have been established.

P947dST-Tiso index, a new shallow ECG marker in response to ajmaline for predicting ventricular fibrillation induction in Brugada patients

Abstract Introduction - No study has been performed to investigate the role of drug-induced ECG morphology modifications as potential risk factors for the development of malignant arrhythmias in patients with Brugada syndrome. Purpose - The aim of this study is to introduce a new index to improve asymptomatic patient stratification and to report the first case of a patient with Brugada syndrome undergoing ajmaline testing that has been evaluated using a diagnostic 252-lead ECG vest. Methods - From December 2018 to April 2019, 26 consecutive patients [mean age 39.9 (30–59) years, 18 male] with no cardiovascular risk factors underwent ajmaline testing. By evaluating ECG recordings after ajmaline administration, we calculated an index that we called "dST-Tiso", that is the duration of the positive component of the ST-T wave to the isoelectric line, in V1 and/or V2. Results- Out of 26 patients, 16 (61.5%) had a positive test, with type 1 (coved-type) ECG diagnostic pattern in leads V1-V2 from the 2nd, 3rd and 4th intercostal spaces. The mean recorded dST-Tiso value was 239 ± 76 ms. The ECG showed T-wave above the isoelectric line in 5 patients with a significantly higher dST-Tiso value (on average 360 ± 56 ms), and biphasic T-waves below the isoelectric line in 11 patients with a dST-Tiso value of 209 ± 42 ms (Mann-Whitney, p = 0.039). All patients with positive ajmaline test underwent programmed electrical stimulation (PES). Ventricular fibrillation was induced during PES in all 5 patients with stretched dST-Tiso. In the remaining 11 patients without stretched dST-Tiso, no ventricular arrhythmia was induced by PES. Fig 1 Moreover, using non-invasive high-density electrocardiographic mapping (252-lead ECG vest), 3 patients with dST-Tiso positive pattern received a second ajmaline protocol, with assessment of both the depolarization and repolarization phases. Conclusion - The ECG pattern of prolonged dST-Tiso seems to have a significant impact on safety during PES and may have potential for stratifying risk of sudden death in patients with PES-induced ventricular tachycardia/fibrillation. Abstract Figure 1. Patients’ flowchart.

Update on long QT syndrome.

Long QT syndrome (LQTS) is an inherited disorder characterized by a prolonged QT interval in the 12-lead electrocardiogram and increased risk of malignant arrhythmias in patients with a structurally normal heart. Since its first description in the 1950s, advances in molecular genetics have greatly improved our understanding of the cause and mechanisms of this disease. Sixteen genes linked to LQTS have been described and genetic testing had become an integral part of the diagnosis and risk stratification. This article provides an updated review of the genetic basis, diagnosis, and clinical management of LQTS.

High Voltage J-Waves as a Predictor of Death in Acute ST-Segment Elevated Myocardial Infarction in Hospital

Aims: Stratification of the risk of malignant arrhythmias in patients with coronary artery disease remains a challenge. This study evaluated the potential of high voltage J-waves in patients with acute ST-segment elevated myocardial infarction (STEMI) to predict the risk of malignant arrhythmias during hospitalization. Methods: A total of 128 consecutive STEMI patients with J-waves were enrolled within 48 h after the onset of the STEMI in this prospective study. The mean age was 62.97 ± 12.1 years, and 108 patients were male. Both 12-lead electrocardiograms (ECGs) and right-sided chest lead ECGs were recorded simultaneously within 10 min of admission to the hospital. Continuous ECG monitoring was administered from admission until discharge. Clinical characteristics and ECG parameters were compared between patients who survived and those who died during hospitalization. Results: Malignant ventricular arrhythmias (MVAs) were seen with J-waves more frequently in STEMI patients who subsequently died (P < 0.05). J-wave voltage, QTDc, Tp-e, and the Tp-e/QT ratio increased significantly in patients who died (P < 0.05). Multivariate logistic regression analysis revealed that J-wave voltage (odds ratio [OR], 89.09; 95% confidence interval [CI], 2.606-3045.108; P < 0.05) and MVAs (OR, 4.296; 95% CI, 1.348–13.693; P < 0.05) were associated with the occurrence of sudden death in patients with STEMI during hospitalization. Conclusions: High voltage J-waves are a potential ECG parameter for predicting sudden death in patients with STEMI during hospitalization.

Mortality and incidence of malignant arrhythmias in patients with dilated cardiomyopathy and implantable cardioverter defibrillator in primary and secondary prevention

Mortality and incidence of malignant arrhythmias in patients with dilated cardiomyopathy and implantable cardioverter defibrillator in primary and secondary prevention

Ischemic QRS prolongation as a predictor of ventricular fibrillation in a canine model

Objectives. An acute coronary occlusion and its possible subsequent complications is one of the most common causes of death. One such complication is ventricular fibrillation (VF) due to myocardial ischemia. The severity of ischemia is related to the amount of coronary arterial collateral flow. In dog studies collateral flow has also been shown to be associated with QRS prolongation. The aim of this study was to investigate whether ischemic QRS prolongation (IQP) is associated with impending VF in an experimental acute ischemia dog model. Methods. Degree of IQP and occurrence of VF were measured in dogs (n = 21) during coronary occlusion for 15 min and also during subsequent reperfusion (experiments conducted in 1984). Results. There was a significant difference in absolute IQP between dogs which developed VF during reperfusion (47 ± 29 ms, mean ± SD) and those which did not (12 ± 10 ms; p = .001). Conclusions. IQP during acute coronary occlusion is associated with reperfusion VF in an experimental dog model and might therefore be a potential predictor of malignant arrhythmias in patients with acute coronary syndrome.

Fibrosis-Induced Abnormalities of the Cardiac Conduction System and Malignant Arrhythmias in Patients with Chagas Disease

Fibrosis-Induced Abnormalities of the Cardiac Conduction System and Malignant Arrhythmias in Patients with Chagas Disease

Association of sleep-disordered breathing and malignant arrhythmias in patients with ischemic and dilated cardiomyopathy

Sleep-disordered breathing (SDB) has so far been a neglected comorbidity in patients with cardiac arrhythmias. Recently however, several studies have revealed a correlation between SDB and malignant ventricular arrhythmias. This review article is intended to provide the reader with an update on the pathophysiological association between SDB and ventricular arrhythmias, available clinical data, and therapeutic options.

Risk of arrhythmia induced by psychotropic medications: a proposal for clinical management

Several drugs used in the treatment of mental diseases are associated with an increased risk of sudden cardiac death (SCD). A general cause-relationship between the intake of these drugs and SCD is unattainable, but numerous case reports of drug-induced malignant arrhythmia and epidemiological studies, associating the use of specific drugs with SCD, strongly support the presence of an increased risk. Whereas the absolute risk of drug-induced life-threatening arrhythmia may be relatively low, even small increments in risk of SCD may have a major health impact considering that millions of patients are treated with psychotropics. In subgroups of pre-disposed patients, e.g. patients with cardiac diseases or other co-morbidities, the elderly or patients treated with other negatively interacting drugs, the absolute risk of drug-induced arrhythmia may be considerable. On the other hand, several of the major mental disorders are associated with a large risk of suicide if untreated. The observed risk of malignant arrhythmia associated with treatment with psychotropic drugs calls for clinical guidelines integrating the risk of the individual drug and other potentially interacting risk factors. In this review, data from various authorities on the risk of arrhythmia associated with psychotropic medications were weighted and categorized into three risk categories. Additionally, we suggest a clinically applicable algorithm to reduce the risk of malignant arrhythmia in patients to be treated with psychotropic medications. The algorithm integrates the risk categories of the individual drugs and pre-disposing risk factors and suggests a prudent follow-up for patients with an increased risk. We believe this clinically manageable guideline might improve safety in the many and rapidly increasing number of patients on psychotropic drugs.

Usefulness of catestatin to predict malignant arrhythmia in patients with acute myocardial infarction

Catestatin (CST) displays potent vasodilatory effect and acts on lowering blood pressure in vivo. The clinical utility of CST in patients with acute myocardial infarction (AMI) has not been clearly delineated. The aim of this study was to investigate the predictive value of CST for the development of in-hospital malignant arrhythmia and other adverse cardiac events in patients with AMI. A total of 125 consecutive patients diagnosed with AMI were included. The clinical characteristics and previous history of the patients were collected. Malignant arrhythmia and other major adverse cardiac events (MACE) such as postinfarction angina pectoris or reinfarction and death were recorded during hospitalization. The levels of plasma CST, norepinephrine (NE) and amino-terminal pro-brain sodium peptides (NT-proBNP) were determined by sandwich ELISA. A multiple logistic regression model was used to predict the influence factors of malignant arrhythmia and other MACE during hospitalization of AMI patients. The results showed that the levels of plasma cystatin-C (CysC), high sensitivity C-reactive protein (hs-CRP), NE and NT-proBNP increased in a CST concentration dependent manner. The incidence of malignant arrhythmia significantly increased as the elevation of CST level (P<0.05). Age, CST and NT-proBNP were independent predictors for the MACE occurred during hospitalization. Increased blood glucose (≥6.1mmol/L) and CST were independent predictors for the complicated malignant arrhythmia of AMI patients. These data demonstrated that CST can be used as a new biological marker for prediction of malignant arrhythmia in patients with AMI.

A Novel ECG-Index for Prediction of Ventricular Arrhythmias in Patients after Myocardial Infarction

Risk prediction of ventricular arrhythmias after myocardial infarction (MI) is still insufficient. Prolonged QTc is a known risk marker of mortality and ventricular arrhythmias. QTc has not achieved clinical importance in predicting arrhythmic events in patients after MI. Recent studies have displayed that the terminal part of the QT-interval, Tpeak to Tend (TpTe), may be a more promising predictor of adverse outcome. Herein, we assessed whether TpTe may serve as a predictor of ventricular arrhythmias in patients with previous MI fulfilling current implantable cardioverter-defibrillator (ICD) indications. Seventy-six patients with previous MI eligible for ICD therapy were prospectively enrolled. ECG measurements at baseline were recorded using a 12-lead ECG with 50 mm/s paper speed. TpTe was measured from peak of the T wave to end of T wave. Events during follow up were defined as ventricular arrhythmias requiring appropriate ICD therapy, including antitachycardia pacing and shock. During 23 ± 19 months, arrhythmic events occurred in 36 (47%) patients. TpTe was longer in ICD patients with recorded ventricular arrhythmias compared with those without (116 ± 26 ms vs. 102 ± 20 ms; P = 0.01), whereas ejection fraction (EF) at baseline did not differ (35 ± 9% vs. 35 ± 11%; P = 0.87). TpTe was an independent predictor of ventricular arrhythmias when adjusted for age, EF and QRS duration (HR 1.16; 95% CI 1.03-1.31; P = 0.02). TpTe predicted malignant arrhythmias in patients after MI independently of EF. TpTe may contribute in the risk stratification of patients to identify post-MI patients disposed to malignant arrhythmias and their need of ICD therapy.

Mutation analysis of RyR2 gene in patients after arrhythmic storm

IntroductionMutations of RyR2 gene encoding calcium channel of sarcoplazmatic reticulum are the cause of congenital catecholaminergic polymorphic ventricular tachycardia. The aim of this study was to test the hypothesis that RyR2 variants can increase occurrence of malignant arrhythmias in patients with structural heart diseases. MethodsThe investigated group consisted of 36 patients with structural heart diseases with ICD implanted who suffered arrhythmic storm. In the control group there were 141 patients with coronary artery disease who were hospitalized at our department owing to an acute coronary event and they were alive at least 3 years after the index event. Thus, they could be considered as a group with a low risk of sudden cardiac death. In all of them mutation analysis of RyR2 gene was performed. ResultsWe detected 16 different sequence changes of RyR2 gene in both groups. None of the found nucleotide polymorphisms led to amino acid changes, were located close to splice sites or had any similarity to known splicing enhancer motifs. The occurrence of these variants was not different in both groups. ConclusionsThe prevalence of RyR2 gene variants was not different in cases versus controls suggesting a limited role of this gene in the arrhythmogenesis in structural heart disease patients.