Mina Attin

Basic Concepts of Optical Mapping Techniques in Cardiac Electrophysiology

Optical mapping is a tool used in cardiac electrophysiology to study the heart’s normal rhythm and arrhythmias. The optical mapping technique provides a unique opportunity to obtain membrane potential recordings with a higher temporal and spatial resolution than electrical mapping. Additionally, it allows simultaneous recording of membrane potential and calcium transients in the whole heart. This article presents the basic concepts of optical mapping techniques as an introduction for students and investigators in experimental laboratories unfamiliar with it.

Mechanistic insights into ventricular arrhythmias from mapping studies in humans.

Sudden cardiac death in patients with organic heart disease is usually due to ventricular tachycardia (VT) degenerating to ventricular fibrillation (VF).1 In many cases, implantable cardiac defibrillators (ICDs) have been successful in treating these lethal arrhythmias. However, for the large number of at-risk patients who either do not receive ICDs or who fail to meet criteria for ICD implantation, additional treatment approaches are required. Development of novel antiarrhythmic approaches will require an understanding of the electrophysiologic (and ultimately, cellular) mechanisms that underlie VT and VF in the human heart. Progress in the understanding of VT and VF mechanisms has been made possible by recent technological innovations in cardiac mapping and advances in studying of cellular and molecular aspects of heart disease. Studies in diseased human hearts using three-dimensional electrical mapping (as well as recent optical mapping approaches) have demonstrated the complexity of mechanisms that initiate, maintain and terminate VT, as well as initiate and maintain VF in the heterogeneous myocardial architecture of the diseased human heart. Here we will focus on mechanistic insights into ventricular arrhythmias that have been obtained from such high resolution cardiac mapping studies in patients with ischemic and nonischemic heart disease.

Animation shows promise in initiating timely cardiopulmonary resuscitation: results of a pilot study.

Delayed responses during cardiac arrest are common. Timely interventions during cardiac arrest have a direct impact on patient survival. Integration of technology in nursing education is crucial to enhance teaching effectiveness. The goal of this study was to investigate the effect of animation on nursing students’ response time to cardiac arrest, including initiation of timely chest compression. Nursing students were randomized into experimental and control groups prior to practicing in a high-fidelity simulation laboratory. The experimental group was educated, by discussion and animation, about the importance of starting cardiopulmonary resuscitation upon recognizing an unresponsive patient. Afterward, a discussion session allowed students in the experimental group to gain more in-depth knowledge about the most recent changes in the cardiac resuscitation guidelines from the American Heart Association. A linear mixed model was run to investigate differences in time of response between the experimental and control groups while controlling for differences in those with additional degrees, prior code experience, and basic life support certification. The experimental group had a faster response time compared with the control group and initiated timely cardiopulmonary resuscitation upon recognition of deteriorating conditions (P < .0001). The results demonstrated the efficacy of combined teaching modalities for timely cardiopulmonary resuscitation. Providing opportunities for repetitious practice when a patient’s condition is deteriorating is crucial for teaching safe practice.

A potential impact of nursing characteristics prior to in-hospital cardiac arrest: a self-reported study.

In-hospital cardiac arrest (I-HCA) is a significant public health problem accounting for approximately 200,000 treated cardiac arrests annually in the USA (Morrison et al. 2013). The incidence of I-HCA has been reported to be in the range of 1–5 per 1000 admissions in western countries (Sandroni et al. 2007). The incidence of overall survival to hospital discharge after I-HCA remains less than 30% (Morrison et al. 2013). One way to increase the number of patients who can survive to hospital discharge would be to improve resuscitation training for nurses; the creation of successful training programs that would improve a nurse’s resuscitation knowledge/skills demand a more thorough exploration of nurses’ characteristics. A recent study (Panesar et al. 2014) reported 30 patient safety incidents involving management of cardiac arrests that resulted in death. Poor application of knowledge/skills was among the most common identified weakness in resuscitation management (37%), matched only by equipment deficits. According to a consensus statement by the American Heart Association (AHA) (Morrison et al. 2013), all aspects of I-HCA (e.g. patient safety, training) must be considered a priority to address gaps in science, policy and institutional application and accountability for the care of these patients. Nevertheless, no systematic research has been conducted among nurses to evaluate their current training status (e.g. frequency of training sessions) nor is it known how often nurses encounter I-HCA in different settings. What is known is that rapid deterioration of resuscitative skills has been reported as early as three to six months after training (Smith et al. 2008).

Digitization of Electrocardiogram From Telemetry Prior to In-hospital Cardiac Arrest: A Pilot Study

Background: Analyzing telemetry electrocardiogram (ECG) data over an extended period is often time-consuming because digital records are not widely available at hospitals. Investigating trends and patterns in the ECG data could lead to establishing predictors that would shorten response time to in-hospital cardiac arrest (I-HCA). This study was conducted to validate a novel method of digitizing paper ECG tracings from telemetry systems in order to facilitate the use of heart rate as a diagnostic feature prior to I-HCA. Methods: This multicenter study used telemetry to investigate full-disclosure ECG papers of 44 cardiovascular patients obtained within 1 hr of I-HCA with initial rhythms of pulseless electrical activity and asystole. Digital ECGs were available for seven of these patients. An algorithm to digitize the full-disclosure ECG papers was developed using the shortest path method. The heart rate was measured manually (averaging R-R intervals) for ECG papers and automatically for digitized and digital ECGs. Results: Significant correlations were found between manual and automated measurements of digitized ECGs (p < .001) and between digitized and digital ECGs (p < .001). Bland–Altman methods showed bias = .001 s, SD = .0276 s, lower and upper 95% limits of agreement for digitized and digital ECGs = .055 and −.053 s, and percentage error = 0.22%. Root mean square (rms), percentage rms difference, and signal to noise ratio values were in acceptable ranges. Conclusion: The digitization method was validated. Digitized ECG provides an efficient and accurate way of measuring heart rate over an extended period of time.