Safety threshold of R-wave amplitudes in patients with implantable cardioverter defibrillator.

OBJECTIVE: A safety threshold for baseline rhythm R-wave amplitudes during follow-up of implantable cardioverter defibrillators (ICD) has not been established. We aimed to analyse the amplitude distribution and undersensing rate during spontaneous episodes of ventricular fibrillation (VF), and define a safety amplitude threshold for baseline R-waves. METHODS: Data were obtained from an observational multicentre registry conducted at 48 centres in Spain. Baseline R-wave amplitudes and VF events were prospectively registered by remote monitoring. Signal processing algorithms were used to compare amplitudes of baseline R-waves with VF R-waves. All undersensed R-waves after the blanking period (120 ms) were manually marked. RESULTS: We studied 2507 patients from August 2011 to September 2014, which yielded 229 VF episodes (cycle length 189.6±29.1 ms) from 83 patients that were suitable for R-wave comparisons (follow-up 2.7±2.6 years). The majority (77.6%) of VF R-waves (n=13953) showed lower amplitudes than the reference baseline R-wave. The decrease in VF amplitude was progressively attenuated among subgroups of baseline R-wave amplitude (≥17; ≥12 to <17; ≥7 to <12; ≥2.2 to <7 mV) from the highest to the lowest: median deviations -51.2% to +22.4%, respectively (p=0.027). There were no significant differences in undersensing rates of VF R-waves among subgroups. Both the normalised histogram distribution and the undersensing risk function obtained from the ≥2.2 to <7 mV subgroup enabled the prediction that baseline R-wave amplitudes ≤2.5 mV (interquartile range: 2.3-2.8 mV) may lead to ≥25% of undersensed VF R-waves. CONCLUSIONS: Baseline R-wave amplitudes ≤2.5 mV during follow-up of patients with ICDs may lead to high risk of delayed detection of VF. TRIAL REGISTRATION NUMBER: NCT01561144; results.

Sedación con propofol en los procedimientos de electrofisiología cardiaca / No disponible

En el estado actual de la práctica de la electrofisiología cardiaca invasiva se hace cada vez más necesario que el operador conozca los aspectos de la sedoanalgesia y los datos farmacológicos de los fármacos a utilizar. El propofol se ha erigido como un fármaco conveniente de uso común, en ocasiones asociado a fentanilo para analgesia (AU)

In the current state of the practice of invasive cardiac electrophysiology, it is becoming increasingly necessary for the operator to know the aspects of pharmacological data about sedoanalgesia and drug use. Propofol has emerged as a drug commonly used successfully sometimes associated with fentanyl for analgesia (AU)

Simultaneous Accessory Pathway and AV Node Mechanical Block.

We report a clinical case of a 22-year-old female referred to our institution due to palpitations and preexcitation. Her ECG suggested a right superior paraseptal accessory pathway (AP), which was localised during the electrophysiological study at the superior paraseptal region in close proximity to the His recordings. Reproducible orthodromic reciprocating tachycardia was induced by atrial pacing with extrastimuli. Cryo-mapping performed in the area of earliest atrial activation was not able to terminate the tachycardia. A second attempt, slightly more posterior, caused mechanical block of the AP, which rendered the tachycardia non-inducible. More pressure with the ablation catheter determined a Wenckebach type supra-hisian AV block, which was transient but reproducible. Given this finding no ablation was done. Simultaneous block to the AP and the atrioventricular node has rarely been reported using radiofrequency energy. However, to our knowledge this phenomenon has not been previously reported in large series using cryo-thermal energy.

Polyunsaturated Fatty acids in atrial fibrillation: looking for the proper candidates.

Atrial fibrillation (AF) is the most common sustained arrhythmia encountered in clinical practice with growing prevalence in developed countries. Several medical and interventional therapies, such as atrial specific drugs and pulmonary vein isolation, have demonstrated prevention of recurrences. However, their suboptimal long-term success and significant rate of secondary effects have led to intensive research in the last decade focused on novel alternative and supplemental therapies. One such candidate is polyunsaturated fatty acids (PUFAs). Because of their biological properties, safety, simplicity, and relatively cheap cost, there is a special clinical interest in omega-3 PUFAs as a possible antiarrhythmic agent. Obtained from diets rich in fish, they represent one of the current supplemental therapies. At the cellular level, an increasing body of evidence has shown that n-3 PUFAs exert a variety of effects on cardiac ion channels, membrane dynamic properties, inflammatory cascade, and other targets related to AF prevention. In this article, we review the current basic and clinical evidence pertinent to n-3 PUFAs in AF treatment and prevention. We also discuss controversial outcomes among clinical studies and propose specific subsets of AF patients who will benefit most from n-3 PUFAs.

Pre-hospital delay in acute coronary syndromes: PREDICT CVD-18.

AIMS: To study pre-hospital delay, its components and determinants, in patients with acute coronary syndromes (ACS) admitted to Middlemore Hospital Coronary Care Unit. METHODS: Consecutive ACS patients admitted between January 2009 and July 2010 were included. Pre-hospital delay was defined as the time from onset of worst symptom(s) to defibrillator availability: either ambulance arrival at the scene or time of hospital arrival (non-ambulance patients). RESULTS: For 805 patients the median delay from symptom onset to defibrillator availability was 174 minutes. Half the cohort had a delay to defibrillator availability of >3 hours. The median delay was an hour longer for patients from areas of greatest deprivation compared with less deprived areas, [208 vs 149 min, respectively (p=0.015)], and 7 hours longer for non-ambulance vs ambulance patients, [553 vs 130 min (p<0.001)]. Maori, Pacific, Indian and those from areas of higher deprivation were less likely to travel to hospital by ambulance. Of ST-elevation myocardial infarction patients eligible for reperfusion, over two-thirds of the total delay between symptom onset and reperfusion occurred pre-hospital. CONCLUSION: Community intervention targeted at more disadvantaged communities and higher risk ethnic groups should be considered as part of an overall strategy to reduce disparity and improve cardiac outcomes.

Acute Predict: a clinician-led cardiovascular disease quality improvement project (Predict-CVD 12).

BACKGROUND: New Zealand data demonstrate major disparities in cardiovascular health, particularly by ethnicity and socioeconomic deprivation. ACUTE PREDICT AIM: Acute Predict, the secondary care arm of primary care based PREDICT, is a multidisciplinary project based in the coronary care unit, and is jointly led by nursing and medical staff. The project aim is to ensure patients with acute coronary syndromes (ACS) receive appropriate evidence-based secondary prevention management short- and long-term, regardless of age, socioeconomic status or ethnicity. METHODS AND RESULTS: Acute Predict utilises an electronic backbone to provide the following (1) guideline-based patient-specific decision support, (2) data collection as part of routine clinical workflow, (3) linkage of patients to cardiac rehabilitation and primary care chronic care management programs, (4) clinical and management data capture, (5) real-time whole group and sub-group Key Performance Indicators reporting with drill-down to individual patient data, and (6) long-term tracking of individual patient outcome via linkage to national databases. Over the four years of the project in-hospital provision of cardiac rehabilitation has improved and appropriate discharge medication is high. There are no differences according to ethnicity. Despite this, Maori patients in the Acute Predict ACS cohort are twice as likely as Europeans to have recurrent events post-discharge, even after adjustment for known risk factors. CONCLUSIONS: The built-in real-time data reporting and outcomes/prescribing linkage facilitate monitoring of the quality of CVD prevention activity across the continuum of care. It allows early identification of treatment gaps and of persistent disparities in outcome in our patients. We are learning how best to use this real-time data collection and reporting to support the design and assessment of targeted interventions to close gaps and reduce disparity.