Primary Ventricular Arrhythmias Research Articles

The Relationship Between Primary Ventricular Arrhythmias and In-hospital Mortality and Resuscitated Cardiopulmonary Arrest in Patients with Acute ST Segment Elevation Myocardial Infarction

The Relationship Between Primary Ventricular Arrhythmias and In-hospital Mortality and Resuscitated Cardiopulmonary Arrest in Patients with Acute ST Segment Elevation Myocardial Infarction

Longitudinal Prediction of Ventricular Arrhythmic Risk in Patients With Arrhythmogenic Right Ventricular Cardiomyopathy.

The arrhythmogenic right ventricular cardiomyopathy (ARVC) risk calculator stratifies risk for incident sustained ventricular arrhythmias (VA) at the time of ARVC diagnosis. However, included risk factors change over time, and how well the ARVC risk calculator performs at follow-up is unknown. This was a retrospective analysis of patients with definite ARVC and without prior sustained VA. Risk factors for VA including age, nonsustained ventricular tachycardia, premature ventricular complex burden, T-wave inversions on electrocardiogram, cardiac syncope, right ventricular function, therapeutic medication use, and exercise intensity were assessed at the time of 2010 Task Force Criteria based ARVC diagnosis and upon repeat evaluations. Changes in these risk factors were analyzed over 5-year follow-up. The 5-year risk of VA was predicted longitudinally using (1) the baseline ARVC risk calculator prediction, (2) the ARVC risk prediction calculated using updated risk factors, and (3) time-varying Cox regression. Discrimination and calibration were assessed in comparison to observed VA event rates. Four hundred eight patients with ARVC experiencing 132 primary VA events were included. Matched comparison of risk factors at baseline versus at 5 years of follow-up revealed decreased burdens of premature ventricular complexes (-1200/day) and nonsustained ventricular tachycardia (-14%). Presence of significant right ventricular dysfunction and number of T-wave inversions on electrocardiogram were unchanged. Observed risk for VA decreased by 13% by 5 years follow-up. The baseline ARVC risk calculator's ability to predict 5-year VA risk worsened during follow-up (C statistics, 0.83 at diagnosis versus 0.68 at 5 years). Both the updated ARVC risk calculator (C statistics of 0.77) and time-varying Cox regression model (C statistics, 0.77) had strong discrimination. The updated ARVC risk calculator overestimated 5-year VA risk by an average of +6%. Risk factors for VA in ARVC are dynamic, and overall risk for incident sustained VA decreases during follow-up. Up-to-date risk factor assessment improves VA risk stratification.

Hemodynamic Aberrancies in Left Ventricular Assist Device–Associated Heart Failure Syndromes

Hemodynamic Aberrancies in Left Ventricular Assist Device–Associated Heart Failure Syndromes

Comparison of and Frequency of Mortality, Left Ventricular Assist Device Implantation, Ventricular Arrhythmias, and Heart Transplantation in Patients With Familial Versus Nonfamilial Idiopathic Dilated Cardiomyopathy

We postulated that familial idiopathic dilated cardiomyopathy (F-IDC) is associated with a worse prognosis than nonfamilial IDC (nonF-IDC). Patients with F-IDC had either a strong family history and/or proved genetic mutations. We studied long-term prognosis (mean follow-up: 6.1 ± 4.1 years) of 162 patients with IDC (age: 55.5 ± 17.9 years, men: 57.8%, 50% F-IDC) with an implantable cardioverter-defibrillator or cardiac resynchronization therapy. The primary end point was a composite of death, left ventricular (LV) assist device implant, or heart transplantation. The secondary end point was a ventricular arrhythmia event. There was no significant difference in the prevalence of diabetes, hypertension, New York Heart Association class, medical therapy, and years of follow-up between the F-IDC and nonF-IDC groups. Patients with F-IDC were younger than patients with nonF-IDC (49.1 ± 17.0 years vs 61.6 ± 16.5 years, p <0.001). Mean LV ejection fraction was significantly lower in F-IDC group than in the nonF-IDC group (26 ± 12% vs 31 ± 12%, p=0.022). The primary end point was achieved in 54 patients in F-IDC group (66.7%) versus 19 in the nonF-IDC group (23.5%) (p <0.001). The Kaplan-Meier survival estimates for the composite end point and for ventricular arrhythmia were significantly lower in the F-IDC versus nonF-IDC (log-rank p ≤0.001 and 0.04, respectively). F-IDC was the only multivariable predictor of the primary composite end point (hazard ratio 3.419 [95% confidence interval 1.845 to 6.334], p <0.001). The likelihood of LV remodeling manifested by LV ejection fraction improvement (≥10%) was significantly lower in F-IDC than nonF-IDC (27.1% vs 44.8%, p=0.042). In conclusion, F-IDC is a predictor of mortality, need for LV assist device, or heart transplantation. F-IDC is associated with significantly lower event-free survival for primary end point and ventricular arrhythmia than nonF-IDC. F-IDC has significantly lower likelihood of LV reverse remodeling than nonF-IDC.

Importance of genotype for risk stratification in arrhythmogenic right ventricular cardiomyopathy using the 2019 ARVC risk calculator.

AimsTo study the impact of genotype on the performance of the 2019 risk model for arrhythmogenic right ventricular cardiomyopathy (ARVC).Methods and resultsThe study cohort comprised 554 patients with a definite diagnosis of ARVC and no history of sustained ventricular arrhythmia (VA). During a median follow-up of 6.0 (3.1,12.5) years, 100 patients (18%) experienced the primary VA outcome (sustained ventricular tachycardia, appropriate implantable cardioverter defibrillator intervention, aborted sudden cardiac arrest, or sudden cardiac death) corresponding to an annual event rate of 2.6% [95% confidence interval (CI) 1.9–3.3]. Risk estimates for VA using the 2019 ARVC risk model showed reasonable discriminative ability but with overestimation of risk. The ARVC risk model was compared in four gene groups: PKP2 (n = 118, 21%); desmoplakin (DSP) (n = 79, 14%); other desmosomal (n = 59, 11%); and gene elusive (n = 160, 29%). Discrimination and calibration were highest for PKP2 and lowest for the gene-elusive group. Univariable analyses revealed the variable performance of individual clinical risk markers in the different gene groups, e.g. right ventricular dimensions and systolic function are significant risk markers in PKP2 but not in DSP patients and the opposite is true for left ventricular systolic function.ConclusionThe 2019 ARVC risk model performs reasonably well in gene-positive ARVC (particularly for PKP2) but is more limited in gene-elusive patients. Genotype should be included in future risk models for ARVC.

Prognostic Role of Myocardial Edema as Evidenced by Early Cardiac Magnetic Resonance in Survivors of Out-of-Hospital Cardiac Arrest: A Multicenter Study.

BackgroundSudden cardiac arrest (SCA) may be caused by an acute and reversible myocardial injury, a chronic and irreversible myocardial damage, or a primary ventricular arrhythmia. Cardiac magnetic resonance imaging may identify myocardial edema (ME), which denotes acute and reversible myocardial damage. We evaluated the arrhythmic outcome of SCA survivors during follow‐up and tested the prognostic role of ME.Methods and ResultsWe included a consecutive series of 101 (71% men, median age 47 years) SCA survivors from 9 collaborative centers who underwent early (<1 month) cardiac magnetic resonance imaging and received an implantable cardioverter‐defibrillator (ICD). On T2‐weighted sequences, ME was found in 18 of 101 (18%) patients. According to cardiac magnetic resonance imaging findings, the arrhythmic SCA was ascribed to acute myocardial injury (either ischemic [n=10] or inflammatory [n=8]), to chronic structural heart diseases (ischemic heart disease [n=11], cardiomyopathy [n=20], or other [n=23]), or to primarily arrhythmic syndrome (n=29). During a follow‐up of 47 months (28 to 67 months), 24 of 101 (24%) patients received an appropriate ICD intervention. ME was associated with a significantly higher survival free from both any ICD interventions (log‐rank=0.04) and ICD shocks (log‐rank=0.03) and remained an independent predictor of better arrhythmic outcome after adjustment for left ventricular ejection fraction and late gadolinium enhancement. The risk of appropriate ICD intervention was unrelated to the type of underlying heart disease.ConclusionsME on early cardiac magnetic resonance imaging, which denotes an acute and transient arrhythmogenic substrate, predicted a favorable long‐term arrhythmic outcome of SCA survivors. These findings may have a substantial impact on future guidelines on the management of SCA survivors.

STORMS-A-BREWIN: USE OF SYMPATHECTOMY IN TREATMENT OF REFRACTORY VENTRICULAR TACHYCARDIA STORM PROVOKED BY THYROID STORM IN A PATIENT WITH STRUCTURAL HEART DISEASE

TOPIC: Cardiovascular Disease TYPE: Medical Student/Resident Case Reports INTRODUCTION: Sympathectomy has been used since the 1960s for treatment of refractory ventricular tachycardia (VT)(1). However, the procedure has not been studied with a randomized controlled trial; clear indications and outcome data remain unclear. In this case report, we describe the use of sympathectomy in the treatment of a patient with refractory VT storm provoked by thyroid storm in the setting of underlying structural heart disease. CASE PRESENTATION: The patient is a 60-year-old male with a history of biventricular systolic failure secondary to ischemic cardiomyopathy (ICM). In addition to ICM, he had a history of VT for which he underwent two prior ablations (20 months and 2 months prior to admission) as well as permanent pacemaker implantation. One month prior to presentation, he was diagnosed with hyperthyroidism which was treated with methimazole. He presented to our institution for a clinic appointment but collapsed in our hospital parking garage. He was shocked by his pacemaker 4 times before being brought to our ED where he received an additional 10 shocks. ED staff determined the patient was in VT storm. He was sedated with propofol and intubated for airway protection before admission to the ICU. Thyroid stimulating hormone was found to be undetectable at this time, and free T4 was significantly elevated. Given his presentation and clinical history, he was diagnosed with refractory VT storm secondary to thyroid storm in the setting of structural heart disease. Thyroid storm was treated with standard therapies and VT storm was adequately suppressed with propofol. On hospital day 2, sedation was discontinued, and he was extubated without complication. Unfortunately, he continued to have runs of VT on hospital days 2-6. Given his history of previous ablations and thyroid storm, we elected to pursue bilateral VATS sympathectomy (hospital day 6) before attempting a third ablation (hospital day 10). The ablation was complicated by RV perforation requiring pericardiocentesis. The patient remained VT free from hospital day 6 until discharge on hospital day 12. He has been VT free at subsequent follow up appointments. DISCUSSION: To our knowledge, this is the first reported case involving the use of sympathectomy in the treatment of VT storm provoked by thyroid storm. Arrhythmias caused by thyroid storm are typically atrial in nature, with few reports of primary ventricular arrhythmias. Ventricular arrhythmias in thyroid storm are classically thought to be associated with structural heart disease. CONCLUSIONS: Sympathectomy has been shown to be an effective treatment in refractory VT, but more research is needed in this area to better characterize indications and outcomes(2,3). REFERENCE #1: Estes EH Jr., Izlar HL Jr. Recurrent ventricular tachycardia. A case successfully treated by bilateral cardiac sympathectomy. Am J Med. 1961;31:493-497. REFERENCE #2: Vaseghi M, Gima J, Kanaan C, et al. Cardiac sympathetic denervation in patients with refractory ventricular arrhythmias or electrical storm: intermediate and long-term follow-up. Heart Rhythm. 2014;11(3):360-366. doi:10.1016/j.hrthm.2013.11.028 REFERENCE #3: Vaseghi M, Barwad P, Malavassi Corrales FJ, et al. Cardiac Sympathetic Denervation for Refractory Ventricular Arrhythmias [published correction appears in J Am Coll Cardiol. 2017 Aug 8;70(6):811]. J Am Coll Cardiol. 2017;69(25):3070-3080. doi:10.1016/j.jacc.2017.04.035 DISCLOSURES: No relevant relationships by James Collins, source=Web Response No relevant relationships by John Tepper, source=Web Response

Hydroxychloroquine/Azithromycin Therapy and QT Prolongation in Hospitalized Patients WithCOVID-19.

ObjectivesThis study aimed to characterize corrected QT (QTc) prolongation in a cohort of hospitalized patients with coronavirus disease-2019 (COVID-19) who were treated with hydroxychloroquine and azithromycin (HCQ/AZM).BackgroundHCQ/AZM is being widely used to treat COVID-19 despite the known risk of QT interval prolongation and the unknown risk of arrhythmogenesis in this population.MethodsA retrospective cohort of COVID-19 hospitalized patients treated with HCQ/AZM was reviewed. The QTc interval was calculated before drug administration and for the first 5 days following initiation. The primary endpoint was the magnitude of QTc prolongation, and factors associated with QTc prolongation. Secondary endpoints were incidences of sustained ventricular tachycardia or ventricular fibrillation and all-cause mortality.ResultsAmong 415 patients who received concomitant HCQ/AZM, the mean QTc increased from 443 ± 25 ms to a maximum of 473 ± 40 ms (87 [21%] patients had a QTc ≥500 ms). Factors associated with QTc prolongation ≥500 ms were age (p < 0.001), body mass index <30 kg/m2 (p = 0.005), heart failure (p < 0.001), elevated creatinine (p = 0.005), and peak troponin (p < 0.001). The change in QTc was not associated with death over the short period of the study in a population in which mortality was already high (hazard ratio: 0.998; p = 0.607). No primary high-grade ventricular arrhythmias were observed.ConclusionsAn increase in QTc was seen in hospitalized patients with COVID-19 treated with HCQ/AZM. Several clinical factors were associated with greater QTc prolongation. Changes in QTc were not associated with increased risk of death.

Immediate electrical storm of Torsades de Pointes after CRT-D implantation in an ischemic cardiomyopathy patient

Cardiac resynchronization therapy with an implantable cardioverter-defibrillator (CRT-D) is the preferred treatment for patients with severe heart failure, dyssynchrony, and an increased risk of sudden cardiac death or for primary ventricular arrhythmia survivors. Rarely, left ventricular epicardial pacing can induce ventricular tachyarrhythmia rather than a beneficial effect. We describe an ischemic cardiomyopathy patient who underwent CRT-D therapy and developed sustained torsades de pointes (TdP) immediately after switching to biventricular pacing (BVP) mode. Here, TdP possibly developed owing to the change in the dispersion of repolarization of the left ventricle myocardium. The diagnosis and management of BVP-induced ventricular arrhythmia is discussed.

Long-term outcome of transvenous bipolar atrial leads implanted in children and young adults with congenital heart disease

Atrial leads are often implanted in paediatric patients needing a pacemaker (PM). The aim of this study is the evaluation of their outcome in young patients. We evaluated transvenous atrial leads outcome in children and young adults from a single centre, with a retrospective analysis. A P< 0.05 was considered significant. Between 1992 and 2008, 110 patients, 75 with congenital heart defects (d-transposition of great arteries status/post, s/p, Mustard 41%, atrioventricular septal defect 11%, tetralogy 9%, ventricular septal defect 8%), aged 13.3 ± 5.3 years, underwent PM implantation with bipolar atrial transvenous leads for sinus node dysfunction (50%), atrioventricular block (38%), cardiomyopathies, and primary ventricular arrhythmias (12%). Leads are steroid-eluting (98%), tined (59%), screw-in (41%), polyurethane-insulated (72%), silicone-insulated (28%), and have been positioned by transcutaneous puncture of subclavian vein into right atrial appendage/remnant (RAA, 50%), right atrial free wall/septum (25%), left atrium (s/p Mustard, 25%). Follow-up duration is 6.4 ± 4.8 (range 0.1-18) years. At multivariate analysis, younger age at implant was a risk factor for lead failure (4 leads, 3.5%) (P= 0.03); 16 leads (14%) dislodged post-implantation and 12 were successfully repositioned, the others extracted or abandoned. Dislocation occurred more frequently with screw-in leads (P= 0.03) positioned outside RAA (P= 0.02). Atrial threshold showed a small but significant increase, 0.002 V/month (P< 0.001), impedance showed a decrease (0.6 Ω/month, P< 0.001), P-wave showed no significant difference. Transvenous bipolar atrial leads have good long-term results in young patients, with a very low rate of lead failure. Older age at implant can further reduce this rate. Lead dislodgement is frequent in the post-operative period.

Unifying the definitions of sudden unexpected death in epilepsy

Sudden unexpected death in epilepsy (SUDEP) is a category of death in people with epilepsy occurring in the absence of a known structural cause of death and is most likely heterogeneous with regard to mechanisms and circumstances. SUDEP is particularly difficult to investigate in research studies for several reasons, including its relatively low incidence, its unpredictable occurrence often in unwitnessed settings, and its low rate of complete autopsy examinations. Over the past two decades, two complementary definitions have been used in most SUDEP studies, but often with variations. We propose here a unified SUDEP definition and classification to resolve current ambiguities and to retrieve cases that would not have been further studied if the previous definitions were used. The proposed Unified SUDEP Definition and Classification contains, in addition to concepts inherent in the previous definitions, nine main recommendations. (1) The word "unexpected," and not the word "unexplained," should be uniformly used in the term SUDEP. (2) The SUDEP category should be applied when appropriate, whether or not a terminal seizure is known to have occurred. (3) The "Possible SUDEP" category should be used only for cases with competing causes of death, with cases left unclassified when data are insufficient to reasonably permit their classification. (4) Cases that would otherwise fulfill the definition of SUDEP should be designated as "SUDEP Plus" when evidence indicates that a preexisting condition, known before or after autopsy, could have contributed to the death, which otherwise is classified as SUDEP (e.g., coronary insufficiency with no evidence of myocardial infarction or long-QT syndrome with no documented primary ventricular arrhythmia leading to death). (5) To be considered SUDEP, the death should have occurred within 1 h from the onset of a known terminal event. (6) For status epilepticus as an exclusion criterion for SUDEP, the duration of seizure activity should be 30 min or more. (7) A specific category of SUDEP due to asphyxia should not be designated, the distinction being largely impractical on circumstantial or autopsy evidence, with more than one mechanism likely to be contributory in many cases. (8) Death occurring in water but without circumstantial or autopsy evidence of submersion should be classified as "Possible SUDEP." If any evidence of submersion is present, the death should not be classified as SUDEP. (9) A category of "Near-SUDEP" should be agreed to include cases in which cardiorespiratory arrest was reversed by resuscitation efforts with subsequent survival for more than 1 h. Scenarios that demonstrate the basis for each SUDEP category are described. If disagreement exists about which category fits a particular case, we suggest the use of consensus decision by a panel of informed reviewers to adjudicate the classification of the case.

338 Causes and hospital mortality in a large cohort of out-of-hospital cardiac arrest

The great majority of successfully resuscitated out-of-hospital cardiac arrest (OHCA) patients will subsequently die during their ICU and hospital stay. Several studies have previously described the main causes of OHCA but the impact of aetiology on the outcome and the timing and value of diagnostic procedures such as coronary angiogram remains controversial. We analysed the causes of cardiac arrest in a prospective database from a tertiary reference. We compared the mortality observed in the subgroups of patients with a cardiac or a non-cardiac cause of arrest. 983 patients were admitted from January 2000 to August 2008.In patients without an obvious non-cardiac cause of arrest, a coronary angiogram followed if necessary by a coronary angioplasty was performed at admission. The median age was 58 years (range 84.39) and 74% were male. Past or current cigarette smoking was noted in 54%, hypertension in 35% and hypercholesterolemia in 23%. The causes of OHCA were an acute coronary syndrome (ACS=Gr1) in 389 pts (40%), primary ventricular arrhythmia (VT-FV=Gr2) in 154 pts (16%), cardiac failure (=Gr3) in 35 pts (3%), acute respiratory failure (=Gr4) in 186 pts (19%), neurological failure (=Gr5) in 41 pts (4%), unknown (=Gr6) in 71 pts (7%) and others causes(=Gr7) in 104 pts (11%). Overall, the mortality rate of the entire cohort was 68%; mortality rates observed in each subgroup are displayed in the figure.

Aldosterone and long-term outcome after myocardial infarction: A substudy of the french nationwide Observatoire sur la Prise en charge hospitalière, l'Evolution à un an et les caRactéristiques de patients présentant un infArctus du myocarde avec ou sans onde Q (OPERA) study

High plasma aldosterone levels at presentation are correlated to poor outcome after ST elevation acute myocardial infarction (AMI). Whether there is a relationship between aldosterone levels and outcome in a broader spectrum of patients admitted for AMI defined by the new definition based on troponin levels remains unknown. Plasma aldosterone, C-reactive protein, and brain natriuretic peptide (BNP) were measured in 471 patients, 24 and 72 hours after admission for AMI defined by the new definition. The primary outcome was the composite of death, resuscitated cardiac arrest, recurrent/extended myocardial infarction, recurrent ischemia, heart failure, and stroke. The highest aldosterone levels quartile at 24 hours was significantly associated with the occurrence of the primary outcome (P < .0001), death (P < .05), heart failure (P < .05), ventricular (P < .0001) and supraventricular arrhythmias (P < .05), and acute renal failure (P < .01) during the in-hospital period, and higher rates of mortality (P < .05) at 1-year follow-up. Independent correlates of the primary outcome at 1 year were age > or =73 (odds ratio [OR] 2.22 [1.38-3.57]), heart failure (OR 6.46 [1.99-20.98]), 24-hour aldosterone > or =103.6 pg.mL(-1) (OR 1.72 [1.07-2.77]), and BNP > or =389 pg.mL(-1) (OR 2.35 [1.44-3.84]) concentrations. The model applied to the 72-hour variables, identified the same correlates. Using the new definition of AMI, based on troponin levels, regardless of ST-segment elevation and management strategies, high aldosterone concentration is associated with major adverse in-hospital events and is an independent correlate of clinical outcome at 1 year. These findings warrant trials assessing the benefit of early aldosterone blockade in such patients.

C.A.U.S.E.: Cardiac arrest ultra-sound exam—A better approach to managing patients in primary non-arrhythmogenic cardiac arrest

Cardiac arrest is a condition frequently encountered by physicians in the hospital setting including the Emergency Department, Intensive Care Unit and medical/surgical wards. This paper reviews the current literature involving the use of ultrasound in resuscitation and proposes an algorithmic approach for the use of ultrasound during cardiac arrest. At present there is the need for a means of differentiating between various causes of cardiac arrest, which are not a direct result of a primary ventricular arrhythmia. Identifying the cause of pulseless electrical activity or asystole is important as the underlying cause is what guides management in such cases. This approach, incorporating ultrasound to manage cardiac arrest aids in the diagnosis of the most common and easily reversible causes of cardiac arrest not caused by primary ventricular arrhythmia, namely; severe hypovolemia, tension pneumothorax, cardiac tamponade, and massive pulmonary embolus. These four conditions are addressed in this paper using four accepted emergency ultrasound applications to be performed during resuscitation of a cardiac arrest patient with the aim of determining the underlying cause of a cardiac arrest. Identifying the underlying cause of cardiac arrest represents the one of the greatest challenges of managing patients with asystole or PEA and accurate determination has the potential to improve management by guiding therapeutic decisions. We include several clinical images demonstrating examples of cardiac tamponade, massive pulmonary embolus, and severe hypovolemia secondary to abdominal aortic aneurysm. In conclusion, this protocol has the potential to reduce the time required to determine the etiology of a cardiac arrest and thus decrease the time between arrest and appropriate therapy.

Mort subite cardiaque d'origine génétique

Sudden death is defined as an unexpected death due to a cardiac cause, which occurs within one hour after the onset of symptoms. Autopsy can provide evidence for an undiagnosed cardiac dilated or hypertrophic cardiomyopathy. In case of negative autopsy, the most presumable cause remains a genetically-determined malignant primary ventricular arrhythmia. Rhythmic sudden cardiac death is most frequently due to a channel disease without any structural heart disease. Primary ventricular arrhythmias include long QT syndrome, Brugada syndrome, short QT syndrome and Polymorphic Ventricular Tachycardia. The diagnosis of such syndromes relies upon specific ECG anomalies, personal history of family members, and eventually the results of echocardiography and drug challenge. For some of these diseases, morbid genes have been identified; this makes possible the management of pre symptomatic or undiagnosed family members by specialized multidisciplinary teams. Rescued sudden death exposes to a high risk of recurrence. In such patients, the automatic implantable defibrillator has dramatically improved survival.

La tachycardie ventriculaire catécholergique du jeune enfant : un diagnostic souvent méconnu

Catecholaminergic polymorphic ventricular tachycardia is important to be diagnosed as an underlying disease in children with syncope and normal heart, because of its poor prognosis. Case report. – A 3-year-old boy was referred for stress and emotion induced syncope. Primary ventricular arrhythmia, consisting of salvos of bidirectional ventricular tachycardia, was reproducibly induced by physical exertion. The syncopal events and severe arrhythmia disappeared with beta-blocking therapy. Conclusion. – Despite its rare occurrence, catecholaminergic polymorphic ventricular tachycardia is an important cause of stress and emotion induced syncope and sudden death in children.

Cardiomyoplasty for treatment of heart failure.

Cardiomyoplasty for treatment of heart failure.

Relation between myocyte disarray and outcome in hypertrophic cardiomyopathy

Hypertrophic cardiomyopathy (HC) is associated with an increased risk of sudden cardiac death or death from heart failure. Little is known of the pathologic substrate for risk of premature death in this disease. We therefore set out to correlate the pathologic findings with the mode of death and risk profile in 75 patients with HC. Hearts with HC were obtained after death or transplantation. The clinical details were correlated with the macroscopic findings and the percent fibrosis, disarray, and small-vessel disease across 19 sections of each heart. Thirty-nine patients died suddenly, 28 had end-stage heart failure, and 8 died of other causes. Myocyte disarray correlated positively with evidence of ischemia (r = 0.5, p <0.0001), and was greater in patients who died before age 21 years (mean disarray 33% vs 18%, p <0.0001) and in those with an abnormal vascular response to exercise (mean disarray and 30% vs 19%, p = 0.04). Myocardial fibrosis was greater in patients who died in heart failure (mean percent fibrosis was 2.8% versus 0.9%, p = 0.003), and in patients with nonsustained ventricular tachycardia or a high risk fractionation study (4.9% vs 2.7%, p = 0.04, and 6.84% vs 2.8%, p = 0.03, respectively). In conclusion, young patients who die with HC have greater disarray than their older counterparts. In contrast, myocardial fibrosis is the substrate for premature deaths from heart failure and is associated with an increased risk of a primary ventricular arrhythmia.

Genetics of Brugada, long QT, and arrhythmogenic right ventricular dysplasia syndromes

This article outlines the up-to-date understanding of the molecular basis of primary ventricular arrhythmias. Two disorders have recently been well described at the molecular level, the long QT syndromes and Brugada syndrome, and this article reviews the current scientific knowledge of each disease. A third disorder, arrhythmogenic right ventricular dysplasia, which is on the cusp of understanding, will also be described.

Molecular biology of arrhythmic syndromes.

In this review, the up-to-date understanding of the molecular basis of primary ventricular arrhythmias will be outlined. Two disorders have recently been well described at the molecular level, the long QT syndromes and Brugada syndrome, and in this paper we review the current scientific knowledge of each disease.