Come see the softer side of clinical outcomes: Quality-of-life measures in implanted defibrillator trials.
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Atrial Fibrillation↗
Biomedical subjects
William J Groh
Publications and source records attributed to William J Groh.
Increase in ventricular tachycardia frequency after biventricular implantable cardioverter defibrillator upgrade.
We report the case of a patient in whom transvenous left ventricular pacing lead placement at the time of a biventricular upgrade led to an exacerbation of clinical monomorphic ventricular tachycardia (MVT). At implant, slow left ventricular pacing repeatedly induced sustained MVT. However, testing of the biventricular pacing showed no MVT inducibility, and the system was implanted. The patient was readmitted due to multiple episodes of the MVT observed at implant. The MVT was controlled with pharmacotherapy, allowing the patient to continue with biventricular pacing.
Amiodarone↗
Heart rate variability declines with increasing age and CTG repeat length in patients with myotonic dystrophy type 1.
BACKGROUND: Cardiac myopathy manifesting as arrhythmias is common in the neurological disease, myotonic dystrophy type 1 (DM1). The purpose of the present study was to evaluate heart rate variability (HRV) in patients with DM1. METHODS: In a multicenter study, history, ECG, and genetic testing were performed in DM1 patients. RESULTS: In 289 patients in whom the diagnosis of DM1 was confirmed by a prolonged cytosine-thymine-guanine (CTG) repeat length the most common ambulatory ECG abnormality was frequent ventricular ectopy (16.3%). The 24-hour time domain parameters of SDNN (SD of the NN interval) and SDANN (SD of the mean NN, 5-minute interval) declined as age and CTG repeat length increased (SDNN: -8.5 ms per decade, 95% confidence intervals [CI]-12.9, -4.2, -8.7 ms per 500 CTG repeats, CI -15.7, -1.8, r=0.24, P<0.001; SDANN: -8.1 ms per decade, CI -12.4, -3.8, -8.8 ms per 500 CTG repeats, CI -15.7, -1.9, r=0.23, P<0.001). Short-term frequency domain parameters declined with age only (total power: -658 ms2 per decade, CI: -984, -331, r=0.23, P<0.001; low frequency (LF) power -287 ms2 per decade, CI: -397, -178, r=0.30, P<0.001; high frequency (HF) power: -267 ms2 per decade, CI: -386, -144, r=0.25, P<0.001). The LF/HF ratio increased as the patient aged (0.5 per decade, CI: 0.1, 0.9, r=0.13, P=0.03). CONCLUSIONS: In DM1 patients a decline in HRV is observed as the patient ages and CTG repeat length increases.
Adolescent↗
Use of an insertable loop recorder in a myotonic dystrophy patient.
The case of a 66-year-old woman with myotonic dystrophy is presented. This patient underwent implantation of an insertable loop recorder as a participant in a clinical trial. At 1-month follow-up, interrogation of the insertable loop recorder revealed multiple episodes of wide complex tachycardia. She underwent electrophysiologic study, which revealed moderate His-Purkinje disease, focal atrial tachycardia, monomorphic ventricular tachycardia, and ventricular fibrillation. Successful radiofrequency ablation of the focal atrial tachycardia and implantation of a dual-chamber implantable cardioverter defibrillator was performed.
Aged↗
Severity of cardiac conduction involvement and arrhythmias in myotonic dystrophy type 1 correlates with age and CTG repeat length.
INTRODUCTION: Cardiac myopathy manifesting with conduction disturbances and arrhythmias is common in the neurologic disease myotonic dystrophy. We studied whether the severity of cardiac involvement in myotonic dystrophy correlates with the severity of the genetic abnormality cytosine-thymine-guanine (CTG) repeat expansion. METHODS AND RESULTS: History, physical examination, ECG evaluation, and genetic testing were performed in patients with a clinical diagnosis of myotonic dystrophy. In 342 of 385 patients, the diagnosis was confirmed by CTG repeat expansion. In these patients, the muscular disability severity correlated with age and CTG repeat length (r = 0.44, P < 0.001). An arrhythmia diagnosis was present in 19 (5.6%) patients with a likelihood of diagnosis correlating with age (relative risk [RR] 2.2 per decade, 95% confidence intervals [CI] 1.4 to 3.4, P = 0.001) and CTG repeat length (RR 2.9 per 500 repeats, 95% CI 1.5 to 5.4, P = 0.001). ECGs were abnormal in 222 (64.9%) of the patients. Age, CTG repeat length, and male gender were factors found to correlate with ECG conduction abnormalities quantitated by the PR interval (r = 0.43, P < 0.001) and QRS duration (r = 0.32, P < 0.001). A 24-hour ambulatory ECG was abnormal in 95 (29.6%) of 321 recordings. The presence of an abnormality correlated with age (RR 1.5 per decade, 95% CI 1.2 to 1.9, P < 0.001) and CTG repeat length (RR 1.6 per 500 repeats, 95% confidence intervals 1.1 to 2.2, P = 0.01). CONCLUSION: The severity of skeletal and cardiac myopathy in myotonic dystrophy correlates with age and CTG repeat length, suggesting a similar mechanism causing a time-dependent degenerative process.
Adolescent↗
Attitudes of law enforcement officers regarding automated external defibrillators.
OBJECTIVE: To assess the knowledge and attitudes of law enforcement officers regarding treating out-of-hospital cardiac arrest (OHCA) and using automated external defibrillators (AEDs). METHODS: This was a survey conducted among officers serving Marion County, Indiana. RESULTS: Of 1,130 surveys distributed, 929 (82.2%) were returned. Among these officers, 603 (66.4%) were certified in cardiopulmonary resuscitation (CPR) and 103 (11.3%) had received AED training. Most officers had limited knowledge regarding OHCA. A 100-point knowledge score (mean +/- SD: 31.9 +/- 14.3) was higher in officers who had performed CPR while on duty [35.0, 95% confidence interval (95% CI) = 32.9 to 37.2, p = 0.005] and who were AED-trained (40.8, 95% CI = 38.0 to 43.6, p < 0.001). Of the respondents, 367 (40.1%) believed that AED usage by local law enforcement was needed, and 323 (35.6%) stated that they would feel comfortable using an AED if trained. A 100-point attitude score (mean +/- SD: 32.1 +/- 21.0) was higher in officers who had CPR certification (38.2, 95% CI = 35.6 to 40.8), who had performed CPR while on duty (40.6, 95% CI = 37.7 to 43.5), who were AED-trained (39.5, 95% CI = 35.6 to 43.4), and who had improved OHCA knowledge (+3.8 per 10 points knowledge score, 95% CI = 3.0 to 4.7), p < 0.001, all significant factors. CONCLUSIONS: Limited knowledge and negative attitudes of law enforcement officers regarding their involvement in treating OHCA and using AEDs are commonly present. These factors could result in barriers that negatively impact law enforcement AED programs.
Adult↗
Automated external defibrillator (AED) utilization rates and reasons fire and police first responders did not apply AEDs.
OBJECTIVES: To determine the rate at which fire and police first responders (FRs) apply automated external defibrillators (AEDs) and to ascertain reasons for not applying them. METHODS: Twenty-one emergency medical services (EMS) systems whose FRs had been supplied with AEDs by a philanthropic foundation provided data for all out-of-hospital cardiac arrest (OHCA) patients. Data including the incidence of AED application and explanations for not applying AEDs were analyzed using descriptive statistics. RESULTS: A total of 2,456 OHCAs were reported. AED application information was available for 2,439 patients and revealed that FRs had not applied AEDs to 1,025 patients (42%). Fire FRs were more likely than police FRs to have applied AEDs (relative risk 1.87, 95% confidence interval 1.65-2.12). Reasons for not applying AEDs were listed for 664 (65%) of the OHCA patients to whom AEDs had not been applied. The predominant reason the FRs did not apply an AED was that the transporting ambulance defibrillator had already been applied (74%). However, when response times for FRs and the transporting ambulances were compared for these OHCA patients, it was found that the transporting ambulances arrived after the FRs 23% the time, simultaneously with the FRs 45% of the time, and before the FRs only 32% of the time. CONCLUSION: Fire and police FRs did not apply AEDs to a significant number of OHCA patients. Use of the transport ambulance defibrillator was the primary reason given for not applying the FR AED. Given low AED application rates by FRs, future studies are needed to determine the characteristics of communities in which equipping FRs with AEDs is the most beneficial deployment strategy, and how to increase AED application by FRs in communities with FR AED programs.
Adult↗
Law Enforcement Agency Defibrillation (LEA-D): proceedings of the National Center for Early Defibrillation Police AED Issues Forum.
Why does LEA-D intervention seem to work in some systems but not others? Panelists agreed that some factors that delay rapid access to treatment, such as long travel distances in rural areas, may represent insurmountable barriers. Other factors, however, may be addressed more readily. These include: absence of a medical response culture, discomfort with the role of medical intervention, insecurity with the use of medical devices, a lack of proactive medical direction, infrequent refresher training, and dependence on EMS intervention. Panelists agreed that successful LEA-D programs possess ten key attributes (Table 6). In the end, the goal remains "early" defibrillation, not "police" defibrillation. It does not matter whether the rescuer wears a blue uniform--or any uniform, for that matter--so long as the defibrillator reaches the victim quickly. If LEA personnel routinely arrive at medical emergencies after other emergency responders or after 8 minutes have elapsed from the time of collapse, an LEA-D program will be unlikely to provide added value. Similarly, if police frequently arrive first, but the department is unwilling or unable to cultivate the attributes of successful LEA-D programs, efforts to improve survival may not be realized. In most communities, however, LEA-D programs have tremendous lifesaving potential and are well worth the investment of time and resources. Law enforcement agencies considering adoption of AED programs should review the frequency with which police arrive first at medical emergencies and LEA response intervals to determine whether AED programs might help improve survival in their communities. It is time for law enforcement agency defibrillation to become the rule, not the exception.
Cardiopulmonary Resuscitation↗
Law Enforcement Agency Defibrillation (LEA-D): position statement and best practices recommendations from the National Center for Early Defibrillation.
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Benchmarking↗
A comparison of first-responder automated external defibrillator (AED) application rates and characteristics of AED training.
OBJECTIVE: To determine whether there were associations between the characteristics of first-responder automated external defibrillator (AED) training and AED application rates. METHODS: This multicenter retrospective cohort study analyzed data from ten emergency medical services systems where first responders were trained and equipped with AEDs. Data were provided for all out-of-hospital cardiac arrests (OHCAs) occurring over two years, including whether the first-responder AED was applied (pads attached to patient). Systems were surveyed to determine the characteristics of their initial and continuing AED training. Data were analyzed using odds ratios (ORs) with 95% confidence intervals (95% CIs). RESULTS: Overall, the first-responder AED was applied to 53% of 2,181 OHCAs. First responders applied AEDs to 60% of OHCAs when a national AED training curriculum was used and to 49% of OHCAs when a locally created curriculum was used (OR=1.58; 95% CI=1.32-1.88). First responders applied AEDs to 61% of OHCAs when they were trained to the level of Certified First Responder or higher and to 28% of OHCAs when they were trained only in cardiopulmonary resuscitation (OR=3.97; 95% CI=3.20-4.93). First responders applied AEDs to 66% of OHCAs when they each had an opportunity to apply the AED during continuing training and to 17% of OHCAs when they did not have this opportunity (OR=9.04; 95% CI=7.15-11.42). First responders applied AEDs to 59% of OHCAs when they had not received continuing training within one year of their initial training and to 42% of OHCAs when they had received continuing training in the first year (OR=2.00; 95% CI=1.67-2.40). CONCLUSION: Use of a national AED training curriculum, training to the level of Certified First Responder or higher, and the ability for each first responder to apply the AED during continuing training were associated with higher AED application rates. Continuing training within the first year did not appear to be as important as actually using the AED during the training.
Advanced Cardiac Life Support↗