Plasma big endothelin-1 is an effective predictor for ventricular arrythmias and end-stage events in primary prevention implantable cardioverter-defibrillator indication patients

Objective To investigate whether plasma big endothelin-1(ET-1) predicts ventricular arrythmias(VAs) and end-stage events in primary prevention implantable cardioverter-defibrillator(ICD) indication patigents. Methods In total, 207 patients fulfilling the inclusion criteria from Fuwai Hospital between January 2013 and December 2015 were retrospectively analyzed. The cohort was divided into three groups according to baseline plasma big ET-1 tertiles: tertile 1(< 0.38 pmol/L, n = 68), tertile 2(0.38–0.7 pmol/L, n = 69), and tertile 3(> 0.7 pmol/L, n = 70). The primary endpoints were VAs. The secondary endpoints were end-stage events comprising all-cause mortality and heart transplantation. Results During a mean follow-up period of 25.6 ± 13.9 months, 38(18.4%) VAs and 78(37.7%) end-stage events occurred. Big ET-1 was positively correlated with NYHA class(r = 0.165, P = 0.018), serum creatinine concentration(Scr;r = 0.147, P = 0.034), high-sensitivity C-reactive protein(hs-CRP;r = 0.217, P = 0.002), Lg NT-pro BNP(r = 0.463, P < 0.001), left ventricular end diastolic diameter(LVEDD;r = 0.234, P = 0.039) and negatively correlated with left ventricular ejection fraction(LVEF;r =-0.181, P = 0.032). Kaplan-Meier analysis showed that elevated big ET-1 was associated with increased risk of VAs and end-stage events(P < 0.05). In multivariate Cox regression models, big ET-1 was an independent risk factor for VAs(hazard ratio(HR) = 3.477, 95% confidence interval(CI): 1.352–8.940, P = 0.010, tertile 2 vs. tertile 1;HR = 4.112, 95% CI: 1.604–10.540, P = 0.003, tertile 3 vs. tertile 1) and end-stage events(HR = 2.804, 95% CI: 1.354–5.806, P = 0.005, tertile 2 vs. tertile 1;HR = 4.652, 95% CI: 2.288–9.459, P < 0.001, tertile 3 vs. tertile 1). Conclusions In primary prevention ICD indication patients, plasma big ET-1 levels can predict VAs and end-stage events and may facilitate ICD-implantation risk stratification.

Pharmacological Treatment for Atrial Fibrillation—Modalities in Equines and Companion Animals

Cardiac arrhythmias are probably more common in horses than in any other domestic animal species where poor performance and exercise intolerance is the most frequent clinical complaint. Atrial fibrillation is a type of cardiac arrhythmia that appears as a common finding during medical examinations in humans, large breed dogs and horses. Clinical presentations are of a particular value in racehorses in high performing activities. Atrial fibrillation is characterized by an irregular heart rhythm, secondary to a primary disease or without any sign of comorbidity. The generation and maintenance of Atrial Fibrillation requires a substrate. Some breeds have a genetic predisposition to developing Atrial Fibrillation. Most cases of Atrial Fibrillation are of the paroxysmal type and self-regulate within a few hours to days without the need for treatment. The focus of this study is on the arrhythmic agents that are used for the treatment of Atrial Fibrillation, therefore other arrhythmic agents may not be included, or are included to demonstrate their effect on increasing, inhibiting or decreasing efficacy when used together with medications for the treatment of Atrial Fibrillation. The “working horse” for the pharmacological treatment of Atrial Fibrillation is Quinidine.

Electrocardiographic changes during induced therapeutic hypothermia in comatose survivors after cardiac arrest

AIM: To assess the safety of therapeutic hypothermia(TH) concerning arrhythmias we analyzed serial electrocardiograms(ECG) during TH.METHODS: All patients recovered from a cardiac arrest with Glasgow < 9 at admission were treated with induced mild TH to 32-34℃. TH was obtained with cool fluid infusion or a specific intravascular device. Twelvelead ECG before,during,and after TH,as well as ECG telemetry data was recorded in all patients. From a total of 54 patients admitted with cardiac arrest during the study period,47 patients had the 3 ECG and telemetry data available. ECG analysis was blinded and performed with manual caliper by two independent cardiologists from blinded copies of original ECG,recorded at 25 mm/s and 10 mm/m V. Coronary care unit staff analyzed ECG telemetry for rhythm disturbances. Variables measured in ECG were rhythm,RR,PR,QT and corrected QT(QTc by Bazett formula,measured in lead v2) intervals,QRS duration,presence of Osborn's J wave and U wave,as well as ST segment displacement and T wave amplitude in leads Ⅱ,v2 and v5.RESULTS: Heart rate went down an average of 19 bpm during hypothermia and increased again 16 bpm with rewarming(P < 0.0005,both). There was a nonsignificant prolongation of the PR interval during TH and a significant decrease with rewarming(P = 0.041). QRS duration significantly prolonged(P = 0.041) with TH and shortened back(P < 0.005) with rewarming. QTc interval presented a mean prolongation of 58 ms(P < 0.005) during TH and a significant shortening with rewarming of 22.2 ms(P = 0.017). Osborn or J wave was found in 21.3% of the patients. New arrhythmias occurred in 38.3% of the patients. Most frequent arrhythmia was non-sustained ventricular tachycardia(19.1%),followed by severe bradycardia or paced rhythm(10.6%),accelerated nodal rhythm(8.5%) and atrial fibrillation(6.4%). No life threatening arrhythmias(sustained ventricular tachycardia,polymorphic ventricular tachycardia or ventricular fibrillation) occurred during TH. CONCLUSION: A 38.3% of patients had cardiac arrhythmias during TH but without life-threatening arrhythmias. A concern may rise when inducing TH to patients with long QT syndrome.

Remote monitoring of implantable defibrillators is associated with fewer inappropriate shocks and reduced time to medical assessment in a remote and rural area

BACKGROUND Implantable cardioverter defibrillators(ICDs)and cardiac resynchronisation therapy with defibrillators(CRT-D)reduce mortality in certain cardiac patient populations.However,inappropriate shocks pose a problem,having both adverse physical and psychological effects on the patient.The advances in device technology now allow remote monitoring(RM)of devices to replace clinic follow up appointments.This allows real time data to be analysed and actioned and this may improve patient care.AIM To determine if RM in patients with an ICD is associated with fewer inappropriate shocks and reduced time to medical assessment.METHODS This was a single centre,retrospective observational study,involving 156 patients implanted with an ICD or CRT-D,followed up for 2 years post implant.Both appropriate and inappropriate shocks were recorded along with cause for inappropriate shocks and time to medical assessment.RESULTS RM was associated with fewer inappropriate shocks(13.6%clinic vs 3.9%RM;P=0.030)and a reduced time to medical assessment(15.1±6.8 vs 1.0±0.0 d;P<0.001).CONCLUSION RM in patients with an ICD is associated with improved patient outcomes.