Win Kuang Shen

2014 AHA/ACC Guideline for the Management of Patients With Valvular Heart Disease A Report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines

Jeffrey L. Anderson, MD, FACC, FAHA, Chair , Jonathan L. Halperin, MD, FACC, FAHA, Chair-Elect , Nancy M. Albert, PhD, CCNS, CCRN, FAHA, Biykem Bozkurt, MD, PhD, FACC, FAHA, Ralph G. Brindis, MD, MPH, MACC, Mark A. Creager, MD, FACC, FAHA[§§][1], Lesley H. Curtis, PhD, FAHA, David DeMets, PhD,

EFFICACY OF IMPLANTABLE CARDIOVERTER-DEFIBRILLATORS FOR THE PREVENTION OF SUDDEN DEATH IN PATIENTS WITH HYPERTROPHIC CARDIOMYOPATHY

BACKGROUND Hypertrophic cardiomyopathy is a genetic disease associated with a risk of ventricular tachyarrhythmias and sudden death, especially in young patients. METHODS We conducted a retrospective multicenter study of the efficacy of implantable cardioverter-defibrillators in preventing sudden death in 128 patients with hypertrophic cardiomyopathy who were judged to be at high risk for sudden death. RESULTS At the time of the implantation of the defibrillator, the patients were 8 to 82 years old (mean [+/-SD], 40+/-16), and 69 patients (54 percent) were less than 41 years old. The average follow-up period was 3.1 years. Defibrillators were activated appropriately in 29 patients (23 percent), by providing defibrillation shocks or antitachycardia pacing, with the restoration of sinus rhythm; the average age at the time of the intervention was 41 years. The rate of appropriate defibrillator discharge was 7 percent per year. A total of 32 patients (25 percent) had episodes of inappropriate discharges. In the group of 43 patients who received defibrillators for secondary prevention (after cardiac arrest or sustained ventricular tachycardia), the devices were activated appropriately in 19 patients (11 percent per year). Of 85 patients who had prophylactic implants because of risk factors (i.e., for primary prevention), 10 had appropriate interventions (5 percent per year). The interval between implantation and the first appropriate discharge was highly variable but was substantially prolonged (four to nine years) in six patients. In all 21 patients with stored electrographic data and appropriate interventions, the interventions were triggered by ventricular tachycardia or fibrillation. CONCLUSIONS Ventricular tachycardia or fibrillation appears to be the principal mechanism of sudden death in patients with hypertrophic cardiomyopathy. In high-risk patients with hypertrophic cardiomyopathy, implantable defibrillators are highly effective in terminating such arrhythmias, indicating that these devices have a role in the primary and secondary prevention of sudden death.

Long-Term Progression and Outcomes With Aging in Patients With Lone Atrial Fibrillation: A 30-Year Follow-Up Study

Background— The long-term natural history of lone atrial fibrillation is unknown. Our objective was to determine the rate and predictors of progression from paroxysmal to permanent atrial fibrillation over 30 years and the long-term risk of heart failure, thromboembolism, and death compared with a control population. Methods and Results— A previously characterized Olmsted County, Minnesota, population with first episode of documented atrial fibrillation between 1950 and 1980 and no concomitant heart disease or hypertension was followed up long term. Of this unique cohort, 76 patients with paroxysmal (n=34), persistent (n=37), or permanent (n=5) lone atrial fibrillation at initial diagnosis met inclusion criteria (mean age at diagnosis, 44.2±11.7 years; male, 78%). Mean duration of follow-up was 25.2±9.5 years. Of 71 patients with paroxysmal or persistent atrial fibrillation, 22 had progression to permanent atrial fibrillation. Overall survival of the 76 patients with lone atrial fibrillation was 92% and 68% at 15 and 30 years, respectively, similar to 86% and 57% survival for the age- and sex-matched Minnesota population. Observed survival free of heart failure was slightly worse than expected (P=0.051). Risk for stroke or transient ischemic attack was similar to the expected population risk during the initial 25 years of follow-up but increased thereafter (P=0.004), although CIs were wide. All patients who had a cerebrovascular event had developed ≥1 risk factor for thromboembolism. Conclusions— Comorbidities significantly modulate progression and complications of atrial fibrillation. Age or development of hypertension increases thromboembolic risk.

Familial atrial fibrillation is a genetically heterogeneous disorder.

OBJECTIVES The aims of this study were to identify and characterize familial cases of atrial fibrillation (AF) in our clinical practice and to determine whether AF is genetically heterogeneous. BACKGROUND Atrial fibrillation is not generally regarded as a heritable disorder, yet a genetic locus for familial AF was previously mapped to chromosome 10. METHODS Of 2,610 patients seen in our arrhythmia clinic during an 18-month study period, 914 (35%) were diagnosed with AF. Familial cases were identified by history and medical records review. Four multi-generation families with autosomal dominant AF (FAF 1 to 4) were tested for linkage to the chromosome 10 AF locus. RESULTS Fifty probands (5% of all AF patients; 15% of lone AF patients) were identified with lone AF (age 41 +/- 9 years) and a positive family history (1 to 9 additional relatives affected). In FAF 1 to 3, AF was associated with rapid ventricular response. In contrast, AF in FAF-4 was associated with a slow ventricular response and, with progression of the disease, junctional rhythm and cardiomyopathy. Genotyping of FAF 1 to 4 with deoxyribonucleic acid markers spanning the chromosome 10q22-q24 region excluded linkage of AF to this locus. In FAF-4, linkage was also excluded to the chromosome 3p22-p25 and lamin A/C loci associated with familial AF, conduction system disease, and dilated cardiomyopathy. CONCLUSIONS Familial AF is more common than previously recognized, highlighting the importance of genetics in disease pathogenesis. In four families with AF, we have excluded linkage to chromosome 10q22-q24, establishing that at least two disease genes are responsible for this disorder.

Management of Patients With Atrial Fibrillation (Compilation of 2006 ACCF/AHA/ESC and 2011 ACCF/AHA/HRS Recommendations) A Report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines

This document is a compilation of the current American College of Cardiology Foundation/American Heart Association (ACCF/AHA) practice guideline recommendations for atrial fibrillation (AF) from the “ACC/AHA/ESC 2006 Guidelines for the Management of Patients With Atrial Fibrillation),”* the “2011 ACCF/AHA/HRS Focused Update on the Management of Patients With Atrial Fibrillation (Updating the 2006 Guideline)”† and the “2011 ACCF/AHA/HRS Focused Update on the Management of Patients With Atrial Fibrillation (Update on Dabigatran).”‡ Updated and new recommendations from 2011 are noted and outdated recommendations have been removed. No new evidence was reviewed, and no recommendations included herein are original to this document. The ACCF/AHA Task Force on Practice Guidelines chooses to republish the recommendations in this format to provide the complete set of practice guideline recommendations in a single resource. ### 1.1. Pharmacological and Nonpharmacological Therapeutic Options #### 1.1.1. Rate Control During AF Class I 1. Measurement of the heart rate at rest and control of the rate using …

Syncope Evaluation in the Emergency Department Study (SEEDS) A Multidisciplinary Approach to Syncope Management

Background—The primary aim and central hypothesis of the study are that a designated syncope unit in the emergency department improves diagnostic yield and reduces hospital admission for patients with syncope who are at intermediate risk for an adverse cardiovascular outcome. Methods and Results—In this prospective, randomized, single-center study, patients were randomly allocated to 2 treatment arms: syncope unit evaluation and standard care. The 2 groups were compared with &khgr;2 test for independence of categorical variables. Wilcoxon rank sum test was used for continuous variables. Survival was estimated with the Kaplan-Meier method. One hundred three consecutive patients (53 women; mean age 64±17 years) entered the study. Fifty-one patients were randomized to the syncope unit. For the syncope unit and standard care patients, the presumptive diagnosis was established in 34 (67%) and 5 (10%) patients (P<0.001), respectively, hospital admission was required for 22 (43%) and 51 (98%) patients (P<0.001), and total patient-hospital days were reduced from 140 to 64. Actuarial survival was 97% and 90% (P=0.30), and survival free from recurrent syncope was 88% and 89% (P=0.72) at 2 years for the syncope unit and standard care groups, respectively. Conclusions—The novel syncope unit designed for this study significantly improved diagnostic yield in the emergency department and reduced hospital admission and total length of hospital stay without affecting recurrent syncope and all-cause mortality among intermediate-risk patients. Observations from the present study provide benchmark data for improving patient care and effectively utilizing healthcare resources.

Epidemiology of reflex syncope

Abstract.Cost-effective diagnostic approaches to reflex syncope require knowledge of its frequency and causes in different age groups. For this purpose we reviewed the available literature dealing with the epidemiology of reflex syncope.The incidence pattern of reflex syncope in the general population and general practice is bimodal with peaks in teenagers and in the elderly. In the young almost all cases of transient loss of consciousness are due to reflex syncope. The life-time cumulative incidence in young females (≅ 50 %) is about twice as high as in males (≅ 25 %). In the elderly, cardiac causes, orthostatic and postprandial hypotension, and the effects of medications are common, whereas typical vasovagal syncope is less frequent. In emergency departments, cardiac causes and orthostatic hypotension are more frequent especially in elderly subjects. Reflex syncope, however, remains the most common cause of syncope, but all-cause mortality in subjects with reflex syncope is not higher than in the general population. This knowledge about the epidemiology of reflex syncope can serve as a benchmark to develop cost-effective diagnostic approaches.

Epinephrine-Induced QT Interval Prolongation: A Gene-Specific Paradoxical Response in Congenital Long QT Syndrome

OBJECTIVE To determine the effect of epinephrine on the QT interval in patients with genotyped long QT syndrome (LQTS). PATIENTS AND METHODS Between May 1999 and April 2001, 37 patients (24 females) with genotyped LQTS (19 LQT1, 15 LQT2, 3 LQT3, mean age, 27 years; range, 10-53 years) from 21 different kindreds and 27 (16 females) controls (mean age, 31 years; range, 13-45 years) were studied at baseline and during gradually increasing doses of intravenous epinephrine infusion (0.05, 0.1, 0.2, and 0.3 microg x k(-1) x min(-1)). The 12-lead electrocardiogram was monitored continuously, and heart rate, QT, and corrected QT interval (QTc) were measured during each study stage. RESULTS There was no significant difference in resting heart rate or chronotropic response to epinephrine between LQTS patients and controls. The mean +/- SD baseline QTc was greater in LQTS patients (500+/-68 ms) than in controls (436+/-19 ms, P<.001). However, 9 (47%) of 19 KVLQT1-genotyped LQT1 patients had a nondiagnostic resting QTc (<460 milliseconds), whereas 11 (41%) of 27 controls had a resting QTc higher than 440 milliseconds. During epinephrine infusion, every LQT1 patient manifested prolongation of the QT interval (paradoxical response), whereas healthy controls and patients with either LQT2 or LQT3 tended to have shortened QT intervals (P<.001). The maximum mean +/- SD change in QT (AQT [epinephrine QT minus baseline QT]) was -5+/-47 ms (controls), +94+/-31 ms (LQT1), and -87+/-67 ms (LQT2 and LQT3 patients). Of 27 controls, 6 had lengthening of their QT intervals (AQT >30 milliseconds) during high-dose epinephrine. Low-dose epinephrine (0.05 microg x kg(-1) x min(-1)) completely discriminated LQT1 patients (AQT, +82+/-34 ms) from controls (AQT, -7+/-13 ms; P<.001). Epinephrine-triggered nonsustained ventricular tachycardia occurred in 2 patients with LQTS and in 1 control. CONCLUSIONS Epinephrine-induced prolongation of the QT interval appears pathognomonic for LQT1. Low-dose epinephrine infusion distinguishes controls from patients with concealed LQT1 manifesting an equivocal QTc at rest. Thus, epinephrine provocation may help unmask some patients with concealed LQTS and strategically direct molecular genetic testing.

2015 Heart Rhythm Society Expert Consensus Statement on the Diagnosis and Treatment of Postural Tachycardia Syndrome, Inappropriate Sinus Tachycardia, and Vasovagal Syncope

Robert S. Sheldon, Blair P. Grubb II, Brian Olshansky, Win-Kuang Shen, Hugh Calkins, Michele Brignole, Satish R. Raj, Andrew D. Krahn, Carlos A. Morillo, Julian M. Stewart, Richard Sutton, Paola Sandroni, Karen J. Friday, Denise Tessariol Hachul, Mitchell I. Cohen, Dennis H. Lau, Kenneth A. Mayuga, Jeffrey P. Moak, Roopinder K. Sandhu, Khalil Kanjwal

Sudden unexpected nontraumatic death in 54 young adults: a 30-year population-based study.

The objective of this study was to evaluate the incidence and correlates of sudden unexpected nontraumatic death among young adults in a well-surveyed population. The incidence and pathogenesis of sudden unexpected nontraumatic death in a young adult population (aged 20 to 40 years old) have not been well defined. All residents 20 to 40 years old from Olmsted County, Minnesota, who had nontraumatic sudden death between 1960 and 1989 were included. Histologic and gross cardiac specimens were examined. The incidence of sudden death was estimated based on the ratio of number of observed events to relative census data for the Olmsted County population from the last 3 decades. Statistical comparisons between age decades were obtained with the chi-square test. Incidence trends were tested using Poisson regression. Of the 54 subjects, 19 were women (4.1/10(5) population annually) and 35 were men (8.7/10(5) population annually). An increase in incidence of sudden death was evident in men. Causes of death included coronary artery disease, noncardiovascular disease, suspected primary arrhythmia, vascular disease, myocarditis, hypertrophic cardiomyopathy, and unknown causes. Gross and histologic features suggestive of right ventricular dysplasia were found in 9 subjects (17%), but 6 of these 9 had other established causes of death. Of the 27 sudden deaths between 1980 and 1989, 9 (33%) had a history of cocaine abuse. A trend in increasing incidence of sudden death in young men is noted. A high prevalence of cocaine abuse was observed in young adults who died suddenly. Histologic features of right ventricular dysplasia were prevalent but were not necessarily the primary cause of death.