Ruchir Sehra

The Public Access Defibrillation (PAD) trial: study design and rationale.

The PAD Trial is a prospective, multicenter, randomized clinical study testing whether volunteer, non-medical responders can improve survival from out-of-hospital cardiac arrest (OOH-CA) by using automated external defibrillators (AEDs). These lay volunteers, who have no traditional responsibility to respond to a medical emergency as part of their primary job description, will form part of a comprehensive, integrated community approach to the treatment of OOH-CA. The study is being conducted at 24 field centers in the United States and Canada. Approximately 1000 community units (e.g. apartment or office buildings, gated communities, sports facilities, senior centers, shopping malls, etc.) were randomized to treatment by trained laypersons who will provide either cardiopulmonary resuscitation (CPR) alone or CPR plus use of an AED, while awaiting arrival of the communitys emergency medical services responders. The primary endpoint is the number of OOH-CA victims who survive to hospital discharge. Secondary endpoints include neurological status, health-related quality of life (HRQL), cost, and cost-effectiveness. Data collection will last approximately 15 months and is expected to be completed in September 2003.

Myocardial injury in children following resuscitation after cardiac arrest

BACKGROUND Myocardial dysfunction occurs immediately after successful cardiac resuscitation. Our purpose was to determine whether measurement of cardiac troponin I in children with acute out-of-hospital cardiac arrest predicts the severity of myocardial injury. METHODS AND RESULTS This prospective, observational study was performed in the Pediatric Intensive Care Unit (PICU) on 24 patients following arrest, ranging in age from 8 months to 17 years. Troponin measurements were obtained on admission, and at 12, 24, and 48 h. Transthoracic echocardiograms were performed within 24 h after admission. Survival to hospital discharge was 29% (7/24). The mean age was 5.9+/-4.6 years for survivors and 4.2+/-5.3 years for non-survivors. The median (range) duration of cardiac arrest times for survivors was 6 min (3 to 63 min) versus 34 min (4 to 70 min) for nonsurvivors (P=0.02). Survivors received 1.3+/-2.2 doses of epinephrine (adrenaline) compared with 2.9+/-1.6 doses for non-survivors (P=0.02). Only one patient had ventricular fibrillation and defibrillation was unsuccessful. The ejection fraction for survivors averaged 73.2+/-11.2%, but for nonsurvivors only 55.4+/-19.8% (P=0.04). Ejection fraction correlated inversely with troponin at 12 h (r=-0.54, P=0.01) and at 24 h (r=-0.59, P=0.02). Circumferential fiber shortening for survivors was 37.5+/-7.8 and 25.5+/-10.7% for nonsurvivors (P=0.02). It also correlated inversely with troponin (r=-0.46, P=0.03 for survivors and r=-0.65, P=0.01, for nonsurvivors). CONCLUSION After cardiac arrest and resuscitation in pediatric patients, the severity of myocardial dysfunction was reflected in troponin I levels.

Transvenous catheter cryoablation for treatment of atrial fibrillation: results of a feasibility study.

Pulmonary vein (PV) isolation using radiofrequency (RF) ablation can induce PV stenosis. Cryoablation may offer a safer alternative energy source for PV isolation. PV isolation with cryoablation was attempted in 31 patients with paroxysmal atrial fibrillation (AF). Event monitors were used to measure the AF episode burden. Serial spiral CT scans were obtained to monitor PV stenosis pre‐ and postcryoablation. Cryoablation was immediately successful for PV isolation in 29 of 31 patients (94%), with 5.9 ± 1.2 months of follow‐up. Additional RF ablation was performed for AF recurrences in seven patients. The remaining 22 patients with a single cryoablation procedure demonstrated a time‐dependent, long‐term reduction in the frequency of AF episodes. At 6 months of follow‐up, 18 of 22 of cryo‐treated only patients (82%) were free of symptomatic AF episodes, and antiarrhythmic drugs were discontinued in 12 of 22 patients. Serial spiral CT scans demonstrated no change in the cryo‐treated PV ostial diameter. PV cryoablation was effective to control paroxysmal AF in most patients. Early recurrences of AF postcryoablation were common, though tended to resolve within 6 months postablation, consistent with a process of reverse atrial remodeling. Cryoablation of the PVs did not cause PV stenosis or other serious adverse events.

Effect of a selection and postoperative care protocol on survival of infants with hypoplastic left heart syndrome

BACKGROUND We report the development and implementation of a program designed to assign patients preoperatively to either transplant or Norwood procedure based on a score derived from known risk factors and to enhance postoperative care of infants undergoing the Norwood procedure. METHODS A weighted score for each of six variables comprised the scoring system: ventricular function, tricuspid regurgitation, ascending aortic diameter, atrial septal defect blood flow characteristics, blood type, and age. The scoring system was used to prospectively assign mortality risk and lead to recommendation of either Norwood procedure or transplantation. RESULTS Survival following the Norwood procedure significantly improved after the management program was implemented (88% versus 40% at 48 hours, 57% versus 10% at 30 days, and 50% versus 10% at 1 year, p < 0.0001 at each time point). The survival of the group that received a score of 7 or less (high risk) who underwent the Norwood procedure was 78% at 48 hours, 44% at 30 days, and 33% at 1 year; survival rates among patients considered lower risk (greater than 7) were 100% at 48 hours and 80% at 30 days and 1 year. Transplant outcomes remained unchanged. CONCLUSIONS We report improved survival following the Norwood procedure after the implementation of an institutional management approach aimed at improving the outcome of infants with hypoplastic left heart syndrome and may help neutralize historical biases toward Norwood procedure or transplantation.

Performance of a New Cardiac Cryoablation System in the Treatment of Cavotricuspid Valve Isthmus‐Dependent Atrial Flutter

We sought to evaluate prospectively the safety and efficacy of cryothermal energy to ablate typical atrial flutter (AFL). Ablation of cardiac tissue using cryothermal energy has recently been developed as an alternative to radiofrequency energy, which may offer certain advantages in the treatment of AFL. This prospective, multicenter nonrandomized study of a new catheter‐based system for the treatment of cavotricuspid isthmus (CTI)‐dependent AFL enrolled patients between 18 and 75 years of age. The CTI dependence of AFL was confirmed at electrophysiologic study with activation mapping and/or entrainment. Patients with atrial septal defect, recent myocardial infarction, left ventricular ejection fraction <0.30, or prior AFL ablation were excluded. Cryoablation of AFL was performed in 48 patients from 11 centers. The procedure was immediately successful in 45 patients (94%), and effective in 30 of 40 patients with complete data available at 6 months. Cryoablation is a promising new treatment of CTI‐dependent AFL refractory to medical therapy. Further improvements in catheter design and intravascular sheaths will be tested in a larger multicenter trial.

Nesiritide improves urine output in severely ill pediatric patients awaiting heart transplantation without severe hypotension

Background: Nesiritide (synthetic B-Natriuretic Peptide) has been shown to improve symptoms and hospitalization in adult patients with severe heart failure via a variety of mechanisms including enhanced diuresis. The major side effect precluding use is hypotension. This medication has not been evaluated in pediatric patients. The objective of this study is to review the use of nesiritide in a severely ill group of pediatric patients.Methods: This study reviews 10 uses of nesiritide in seven pediatric patients (ages 20 35 months old all but one less than 18 months old) who were awaiting cardiac transplantation due to severe congenital heart disease (6) or dilated cardiomyopathy (1). All patients were classified as Status IA on multiple inotrope infusions and diuretics. The study evaluated the effects of nesiritide on blood pressure and urine output values from the day prior to infusion to the final day of the infusion. All values are presented as mean S.D. with Student’s t-testing for statistical significance. Results: Nesiritide was infused for a 10.6 4.1 days at doses of 0.005 to 0.02mcg/kg/min. In one use, the infusionwas discontinued due to concern of hypotension (no significant change from the day prior to infusion on retrospective review). This patient’s infusion was resumed in 2 days. Infusions were continued until subjective patient improvement or cardiac transplant. Urine output (ml/kg/hr) improved by 24% (p 0.05) from preto duringnesiritide (pre 2.6 1.3 vs. during 3.6 1.6). Total urine output (ml) improved by 22% (p 0.05). The figure shows urine output changes with each infusion. There were no changes (p NS) in daily highest and lowest systolic blood pressure related to nesiritide infusion (pre high SBP 102 14 mmHg vs. post high 101 10; pre low SBP 78 11 vs. post low 74 10). Five of the seven patients received cardiac transplantation while two others clinically improved enough to discontinue nesiritide. No other adverse effects of nesiritide were noted. Conclusion: Nesiritide improves urine output without significant hypotension or other adverse effects in severely ill pediatric patients.

Noncontact identification of sleep-disturbed breathing from smartphone-recorded sounds validated by polysomnography

PurposeDiagnosis of obstructive sleep apnea by the gold-standard of polysomnography (PSG), or by home sleep testing (HST), requires numerous physical connections to the patient which may restrict use of these tools for early screening. We hypothesized that normal and disturbed breathing may be detected by a consumer smartphone without physical connections to the patient using novel algorithms to analyze ambient sound.MethodsWe studied 91 patients undergoing clinically indicated PSG. Phase I: In a derivation cohort (n = 32), we placed an unmodified Samsung Galaxy S5 without external microphone near the bed to record ambient sounds. We analyzed 12,352 discrete breath/non-breath sounds (386/patient), from which we developed algorithms to remove noise, and detect breaths as envelopes of spectral peaks. Phase II: In a distinct validation cohort (n = 59), we tested the ability of acoustic algorithms to detect AHI < 15 vs AHI > 15 on PSG.ResultsSmartphone-recorded sound analyses detected the presence, absence, and types of breath sound. Phase I: In the derivation cohort, spectral analysis identified breaths and apneas with a c-statistic of 0.91, and loud obstruction sounds with c-statistic of 0.95 on receiver operating characteristic analyses, relative to adjudicated events. Phase II: In the validation cohort, automated acoustic analysis provided a c-statistic of 0.87 compared to whole-night PSG.ConclusionsAmbient sounds recorded from a smartphone during sleep can identify apnea and abnormal breathing verified on PSG. Future studies should determine if this approach may facilitate early screening of SDB to identify at-risk patients for definitive diagnosis and therapy.Clinical trialsNCT03288376; clinicaltrials.org