Electrocardiographic Manifestations in Patients with COVID-19: Daegu in South Korea.

Background And Objectives: As the coronavirus disease 2019 (COVID-19) spreads worldwide, cardiac injury in patients infected with COVID-19 becomes a significant concern. Thus, this study investigates the impact of several electrocardiogram (ECG) parameters and disease severity in COVID-19 patients.

Methods: Seven medical centers in Daegu admitted 822 patients with COVID-19 between February and April 2020.

Clinical Impact of Implantable Cardioverter-Defibrillator Therapy and Mortality Prediction Model for Effective Primary Prevention in Korean Patients.

Background: Studies on the efficacy of implantable cardioverter-defibrillator (ICD) therapy for primary prevention in Asian patients are relatively lacking compared to those for secondary prevention. Also, it is important to stratify which patients will benefit from ICD therapy for primary prevention.

Methods: Of 483 consecutive patients who received new implantation of ICD in 9 centers in Korea, 305 patients with reduced left ventricular systolic function and/or documented ventricular fibrillation/tachycardia were enrolled and divided into primary (n = 167) and secondary prevention groups (n = 138).

Supraventricular tachyarrhythmias in patients with a persistent left superior vena cava.

Aims: A persistent left superior vena cava (PLSVC) is the most common thoracic venous anomaly. This venous anomaly can impact the evaluation and treatment of supraventricular tachyarrhythmia (SVA). The aim of this study was to assess the proportion and characteristics of PLSVC in adult SVA patients.

Effectiveness of Implantable Cardioverter-Defibrillator Therapy for Heart Failure Patients according to Ischemic or Non-Ischemic Etiology in Korea.

Background And Objectives: This study was performed to describe clinical characteristics of patients with left ventriculars (LV) dysfunction and implantable cardioverter-defibrillator (ICD), and to evaluate the effect of ICD therapy on survival in Yeongnam province of Korea.

Subjects And Methods: From a community-based device registry (9 centers, Yeongnam province, from November 1999 to September 2012), 146 patients with LV dysfunction and an ICD implanted for primary or secondary prophylaxis, were analyzed. The patients were divided into two groups, based on the etiology (73 with ischemic cardiomyopathy and 73 with non-ischemic cardiomyopathy), and indication for the device implantation (36 for primary prevention and 110 for secondary prevention).

Genetic Variation of SCN5A in Korean Patients with Sick Sinus Syndrome.

Background And Objectives: Due to recent studies that have shown an association between the genetic variation of SCN5A and sick sinus syndrome (SSS), we sought to determine if a similar correlation existed in Korean patients with SSS.

Subjects And Methods: We enrolled 30 patients with SSS who showed a sinus pause (longer than 3.0 s) in Holter monitoring, in addition to 80 controls.

The Korean Heart Rhythm Society's 2014 Statement on Antithrombotic Therapy for Patients with Nonvalvular Atrial Fibrillation: Korean Heart Rhythm Society.

In patients with nonvalvular atrial fibrillation (AF), the risk of stroke varies considerably according to individual clinical status. The CHA2DS2-VASc score is better than the CHADS2 score for identifying truly lower risk patients with AF. With the advent of novel oral anticoagulants (NOACs), the strategy for antithrombotic therapy has undergone significant changes due to its superior efficacy, safety and convenience compared with warfarin.

Efficacy and safety of 30-mg fimasartan for the treatment of patients with mild to moderate hypertension: an 8-week, multicenter, randomized, double-blind, phase III clinical study.

Purpose: The standard 60-mg dose of fimasartan, a newly developed selective angiotensin II receptor blocker, is effective and safe for use in patients with mild to moderate hypertension. This study aimed to compare the efficacy and safety of low-dose (30 mg) fimasartan and placebo or valsartan (80 mg) for 8 weeks in patients with mild to moderate hypertension.

Methods: In this randomized trial, 293 patients (219 men; mean age, 54.

Efficacy and safety of antiplatelet-combination therapy after drug-eluting stent implantation.

Background/aims: Combination single-pill therapy can improve cost-effectiveness in a typical medical therapy. However, there is a little evidence about the efficacy and tolerability of combination single-pill antiplatelet therapy after percutaneous coronary intervention (PCI) with drug-eluting stents (DES).

Methods: From June to November 2012, in total, 142 patients who met the following criteria were enrolled: at least 18 years old; successful PCI with DES at least 3 months earlier; and regular medication of aspirin and clopidogrel with no side effects.

Genetic Analysis of SCN5A in Korean Patients Associated with Atrioventricular Conduction Block.

Recent several studies have shown that the genetic variation of SCN5A is related with atrioventricular conduction block (AVB); no study has yet been published in Koreans. Therefore, to determine the AVB-associated genetic variation in Korean patients, we investigated the genetic variation of SCN5A in Korean patients with AVB and compared with normal control subjects. We enrolled 113 patients with AVB and 80 normal controls with no cardiac symptoms.

Role of the alternans of action potential duration and aconitine-induced arrhythmias in isolated rabbit hearts.

Under conditions of Na(+) channel hyperactivation with aconitine, the changes in action potential duration (APD) and the restitution characteristics have not been well defined in the context of aconitine-induced arrhythmogenesis. Optical mapping of voltage using RH237 was performed with eight extracted rabbit hearts that were perfused using the Langendorff system. The characteristics of APD restitution were assessed using the steady-state pacing protocol at baseline and 0.

Isolated double-chambered right ventricle in a young adult.

Double-chambered right ventricle (DCRV) is a rare congenital heart disorder in which the right ventricle is divided by an anomalous muscle bundle into a high pressure inlet portion and a low pressure outlet portion. We report a case of isolated DCRV without symptoms in adulthood, diagnosed through echocardiography, cardiac catheterization and cardiac magnetic resonance imaging.

Effect of valsartan on N-terminal pro-brain natriuretic Peptide in patient with stable chronic heart failure: comparison with enalapril.

Background And Objectives: The plasma concentration of N-terminal pro-brain natriuretic peptide (NT-pro-BNP) is a st-rong prognostic indicator for patients with heart failure (HF) across all stages of the condition. Several clinical trials have de-monstrated convincingly that neurohormonal modulation on the renin angiotensin system (RAS) decreases plasma NT-pro-BNP level and results in favorable outcomes. But there are still limited comparative data on the neuro-hormonal modulatory effects of two RAS inhibitors: angiotensin converting enzyme inhibitor and angiotensin receptor blocker.

Improvement in left ventricular systolic dyssynchrony in hypertensive patients after treatment of hypertension.

Background And Objectives: Left ventricular (LV) dyssynchrony has been commonly detected among hypertensive patients with normal LV systolic function and no evidence of congestive heart failure. The purpose of our study was to assess the changes in LV systolic dyssynchrony (SDS(LV)) among hypertensive patients after antihypertensive treatment, and to determine the relationship between SDS(LV) and other conventional echocardiographic parameters.

Subjects And Methods: Forty one hypertensive patients with normal LV ejection fraction were enrolled.

Left atrial volume index as a predictor for occurrence of atrial fibrillation after ablation of typical atrial flutter.

Purpose: Radiofrequency catheter ablation of the cavotricuspid isthmus (CTI) is effective in the treatment of typical atrial flutter (AFL) and atrial fibrillation (AF). AF and AFL often coexist. However, AF often occurs following successful ablation of CTI.

Left ventricular dyssynchrony in patients showing diastolic dysfunction without overt symptoms of heart failure.

Background/aims: Few studies have assessed left ventricular (LV) dyssynchrony in cases of diastolic dysfunction that do not include overt symptoms of heart failure. We hypothesized that systolic or diastolic dyssynchrony involves unique features with respect to the degree of diastolic impairment in isolated diastolic dysfunction.

Methods: We examined 105 subjects with no history of overt symptoms of heart failure and a left ventricular ejection fraction > 50% for mechanical dyssynchrony using tissue Doppler imaging.

Characteristics of myocardial deformation and rotation in subjects with diastolic dysfunction without diastolic heart failure.

Background And Objectives: There have been very few pathophysiologic studies on isolated diastolic dysfunction. We hypothesized that the characteristics of isolated diastolic dysfunction would be located, on the clinical continuum, between those of a normal heart and diastolic heart failure.

Subjects And Methods: We enrolled 102 subjects who had no history of overt symptoms of heart failure and who had a left ventricular ejection fraction of more than 50%.

The relationship between chronic atrial fibrillation and reduced pulmonary function in cases of preserved left ventricular systolic function.

Background And Objectives: The purpose of this study was to investigate the relationship between chronic atrial fibrillation (AF) and reduced pulmonary function.

Subjects And Methods: Eighty-six chronic AF patients who were enrolled from annual health examination programs were studied using echocardiography and pulmonary function tests (PFT). Echocardiography and PFT matched for age, gender, and year performed were selected by the control group who had normal sinus rhythms.

Relationship between left atrial size and stroke in patients with sinus rhythm and preserved systolic function.

Background/aims: Increased left atrial (LA) size has been proposed as a predictor of poor cardiovascular outcome in the elderly. In the present study, we evaluated the relationship between LA size and stroke in subjects of all ages who presented with preserved left ventricular systolic function (LVSF) and sinus rhythm (SR), and investigated the relationships between LA size and other echocardiographic parameters of diastolic function.

Methods: A total of 472 subjects were enrolled in the study (161 men, 311 women) and divided into the stroke group (n=75) and control group (n=397).

Ectopic atrial arrhythmias arising from canine thoracic veins during in vivo stellate ganglia stimulation.

The purpose of the present study was to determine whether thoracic veins may act as ectopic pacemakers and whether nodelike cells and rich sympathetic innervation are present at the ectopic sites. We used a 1,792-electrode mapping system with 1-mm resolution to map ectopic atrial arrhythmias in eight normal dogs during in vivo right and left stellate ganglia (SG) stimulation before and after sinus node crushing. SG stimulation triggered significant elevations of transcardiac norepinephrine levels, sinus tachycardia in all dogs, and atrial tachycardia in two of eight dogs.

Spontaneous stellate ganglion nerve activity and ventricular arrhythmia in a canine model of sudden death.

Background: Little information is available on the temporal relationship between instantaneous sympathetic nerve activity and ventricular arrhythmia in ambulatory animals.

Objective: The purpose of this study was to determine if increased sympathetic nerve activity precedes the onset of ventricular arrhythmia.

Methods: Simultaneous continuous long-term recording of left stellate ganglion (LSG) nerve activity and electrocardiography was performed in eight dogs with nerve growth factor infusion to the LSG, atrioventricular block, and myocardial infarction (experimental group) and in six normal dogs (control group).

Circadian variations of stellate ganglion nerve activity in ambulatory dogs.

Background: The presence of circadian variations in sympathetic outflow from the stellate ganglia is unclear.

Objectives: The purpose of this study was to continuously record stellate ganglion nerve activity (SGNA) in ambulatory dogs.

Methods: We performed continuous 24-hour left (N = 3) or bilateral (N = 3) SGNA recordings in normal ambulatory dogs using implanted Data Sciences International transmitters.