ECG Tracings Research Articles

My Way of Becoming a Good ECG Reader

My first days of learning about ECG was during the summer of second year at the medical school. I went through the graduation test with very little knowledge about ECG. I started learning ECG by comparing the ECG tracings with the echocardiographic results. However, the echo could not help in case of arrhythmia. So I spent my time reading the “Marriott’s Practical Electrocardiography” – kind of textbook of ECG. It was so boring and I quickly gave up the goal of finishing the book. Then I changed to another strategy. Every time I saw an arrhythmic case, I went back home reading a whole chapter about some entity. This strategy proved to be effective. Gradually my skill of interpreting an ECG was built up. From the point of reading an ECG superficially and making a quick diagnosis (which is erroneous most of the time), I became very tedious in finding subtle abnormal signs. When you work really hard, life always has some rewards. I had been selected to study abroad about cardiac electrophysiology. Nowadays, being the Head of Cardiac Electrophysiology department in my hospital, my daily work is to deal with challenging arrhythmic cases. Interpreting elusive ECG tracings is always a passion for me.

Polymorphism, coupling interval and prematurity index in dogs with degenerative mitral valve disease and ventricular arrhythmias.

Ventricular arrhythmias (VA) are a recognized concern in dogs with degenerative mitral valve disease (DMVD). The coupling interval (CI) and the prematurity index (PI) have been shown to accurately differentiate between benign and malignant VA in people, where ventricular arrhythmias are known to be associated with an increased risk of development of signs of heart failure or sudden death. In this study, we characterized ventricular arrhythmias in dogs with symptomatic and asymptomatic DMVD. Seventy dogs with naturally-occurring DMVD and ventricular arrhythmias were retrospectively studied. A cross-sectional investigation including dogs with either symptomatic (stages C/D; n = 41) or asymptomatic (stages B1/B2; n = 29) DMVD was performed. Electrocardiographic tracings were reviewed to calculate both the CI and PI. In eight dogs these indices were compared with those obtained from both a Holter recording and a standard ECG tracing and no statistical differences were found (CI, p = 0.97; PI, p = 0.17). Even though CI and PI were determined in all animals enrolled in the study, VPC characteristics were only compared between symptomatic and asymptomatic dogs when a 24-h Holter recording was available (n = 49). The PI was different (p = 0.01) between symptomatic (0.65 ± 0.17) and asymptomatic (0.56 ± 0.18) dogs, but CI was considered similar (p = 0.91). Also, the symptomatic dogs had more polymorphic VPC (p = 0.002) and supraventricular arrhythmias (p = 0.0002) than the asymptomatic animals. Polymorphism, and repeating patterns of ventricular premature complexes, were characteristics frequently present in overtly symptomatic animals affected by mitral endocardiosis.

Relationship between acute stress and clinical performance in medical students: a pilot simulation study.

Acute stress has been linked to impaired clinical performance in healthcare settings. However, few studies have measured experienced stress and performance simultaneously using robust measures in controlled experimental conditions, which limits the strength of their findings. In the current study we examined the relationship between acute stress and clinical performance in second-year medical students undertaking a simulated ECG scenario. To explore this relationship in greater depth we manipulated two variables (clinical urgency and cognitive load), and also examined the impact of trait anxiety and task self-efficacy. Second-year medical students were asked to conduct a 12-lead ECG on a simulated patient. Students were randomly assigned to one of four experimental conditions according to clinical urgency (high/low) and cognitive load (high/low), which were manipulated during a handover prior to the ECG. As part of the scenario they were asked to describe the ECG trace to a senior doctor over the phone and to conduct a drug calculation. They then received a performance debrief. Psychological stress and physiological stress were captured (via self-report and heart rate, respectively) and various aspects of performance were observed, including technical competence, quality of communication, work rate and compliance with patient safety checks. Trait anxiety and task self-efficacy were also captured via self-report. Fifty students participated. While there was little impact of experimental condition on stress or performance, there was a significant relationship between stress and performance for the group as a whole. Technical competence was poorer for those reporting higher levels of psychological stress prior to and following the procedure. Neither trait anxiety nor task self-efficacy mediated this relationship. This study has provided evidence for a link between acute stress and impaired technical performance in medical students completing a simulated clinical scenario using real-time measures. The implications for patient safety and medical education are discussed.

Quantitative Assessment of the Physiological Parameters Influencing QT Interval Response to Medication: Application of Computational Intelligence Tools.

Human heart electrophysiology is complex biological phenomenon, which is indirectly assessed by the measured ECG signal. ECG trace is further analyzed to derive interpretable surrogates including QT interval, QRS complex, PR interval, and T wave morphology. QT interval and its modification are the most commonly used surrogates of the drug triggered arrhythmia, but it is known that the QT interval itself is determined by other nondrug related parameters, physiological and pathological. In the current study, we used the computational intelligence algorithms to analyze correlations between various simulated physiological parameters and QT interval. Terfenadine given concomitantly with 8 enzymatic inhibitors was used as an example. The equation developed with the use of genetic programming technique leads to general reasoning about the changes in the prolonged QT. For small changes of the QT interval, the drug-related IKr and ICa currents inhibition potentials have major impact. The physiological parameters such as body surface area, potassium, sodium, and calcium ions concentrations are negligible. The influence of the physiological variables increases gradually with the more pronounced changes in QT. As the significant QT prolongation is associated with the drugs triggered arrhythmia risk, analysis of the role of physiological parameters influencing ECG seems to be advisable.

Zbrinjavanje pacijenata sa AKS u GZZHMP Beograd

Introduction. Treating patients suffering from acute myocardial infarction with ST elevation (STEMI) represents a challenge and new treatment possibilities with better outcomes are always sought. The Emergency Medical Aid Service holds the key role in prehospital care of patients with STEMI and administers dual antiplatelet therapy: MONA (Morphine, Oxygen, Nitroglycerin, Aspirin) + clopidogrel or ticagrelor, with the aim of enhancing the reperfusion effect. Objective: To determine the incidence of prehospital treatment of STEMI with dual antiplatelet therapy, as well as the time passed from the first contact with the 194 operator to the admission of the patient to the hospital. Methods: Retrospective analysis of the period between January 1st 2014. and December 31st 2017. The diagnosis was based on medical history as described by the patient, clinical findings and ecg tracings. In patients diagnosed with STEMI, dual antiplatelet therapy was administered and monitored. Time passed from the first contact with the 194 operator to admission to the hospital was also measured. Results: Out of the total number of 8843 patients with acute coronary syndrome, who were treated by the Emergency Medical Aid Service, 2982 were diagnosed with STEMI. Dual antiplatelet therapy was administered to 40.29% of the patients in 2014, while that percentage grew to 70.01% in 2017. Of that percentage in 2017, 60.38% received MONA and ticagrelor, while 9.63% received MONA and clopidogrel. Women have been proven to suffer from STEMI at a later age (70.17±13.05 years of age) than men (61.89±13.43 years of age). Also, 75% of the patients are admitted to the hospital within 65.77 minutes from the moment of the first contact with the 194 operator. Conclusion: During the period in question, a significant rise in application of antiplatelet therapy has been noted. The transfer time of STEMI patients is an important factor of prehospital treatment. Continuous education of Emergency Medical Aid teams enables advances of diagnostic and therapeutic measures in prehospital conditions. .

A Comparasion of Laboratory and Cardiopulmonary Effects of Desflurane, Detomidine and Medetomidine Anaesthetic Combinations in Horses

Background: Equine anesthesia morbidity and mortality rates are greater than in other domestic animals because of hypotension and hypoventilation. The important features desired in general anesthesia for horses are a rapid effect, rapid emergence and balanced anesthesia. The long duration of action of currently used anesthetic agents cause various complications in horses. The aim of the present study was to compare the clinical effects of combination of the anesthetics desflurane, detomidine and medetomidine in horses.Materials, Methods & Results: Eight healthy mixed-breed horses (four males and four females) with weighing 275 ± 56 kg [mean ± standard deviation (SD)] and aged 6.8 ± 5 years [(mean ± SD)] were used for this study. The horses were placed into one of four groups: group I (detomidine-desflurane), group II (detomidine-desflurane-atipamezole), group III (medetomidinedesflurane), or group IV (medetomidine-desflurane-atipamezole). Horses were rested for 15 days before each group starts to study. Intravenous detomidine (25 µg/kg) was used for premedication in groups I and II, and intravenous medetomidine (7 µg/ kg) was used for premedication in groups III and IV. Ketamine hydrocholoride (2 mg/kg) and midazolam (0.03 mg/kg) were intravenously administered in the same syringe to induce anesthesia. After induction of anesthesia, horses were placed in the left lateral recumbent position, and the trachea was intubated with a cuffed endotracheal tube with an internal diameter of 28 mm. The endotracheal tube was attached to a large animal circle breathing system anesthesia machine, and anesthesia was maintained with desflurane for 90 min. The initial dosage of desflurane was 14% + 4 L O2/min, and was reduced by 2% every 10 min over the first 30 min of anesthesia. After 30 min, the desflurane dose was changed to 8% + 4 L, which was maintained until the end of anesthesia (90 min). After 90 min, the administration of desflurane was discontinued, and all animals were supported by O2, with groups II and IV receiving 0.06 mg/kg atipamezole in addition to oxygen. Anaesthetic action times, hematological parameters, blood gas levels, electrolyte levels, biochemical values, electrocardiography values and end-tidal carbon dioxide volume were measured before, during, at the end of, and 24 h after anesthesia.Discussion: In this study, medetomidine (7 µg/kg) and detomidine (25 µg/kg) were intravenously administered, which was adequate and suitable for sedating horses. At the end of anesthesia, 0.06 mg/kg atipamezole was intravenously administered in groups II and IV. However, atipamezole did not affect the clinical parameters. Stress, excitement, fear, catecholamine exchange in blood circulation, hyperglycemia, and hypoxia can all cause changes in venous blood parameters. These are potential reasons for the changes in venous blood parameters (i.e., WBC and Hb) observed at the beginning of and during anesthesia in the present study. During and after the anesthetic period, serum biochemical values can be different from baseline values. They are dependent on the effects of anesthetic agents. During anesthesia, the decrease and increase of biochemical values stabilize the changes in the enzyme system that develops because of the effects of anesthetic agents. In the present study, it was considered that the changes in the biochemical values aimed to stabilize the changes induced by anesthesia. Regarding the electrolyte parameters evaluated in the study, there was a statistical difference detected in Na values between 90 min after induction of anesthesia and 24 h after induction of anesthesia in group IV. However, in previous studies, the changes in Na values did not influence the cardiac pressure during general anesthesia. In our study, significant changes were not seen in any electrolyte parameters except Na, and atrioventricular block was not detected in ECG traces. Generally, decreased ETCO2 levels are evidence of lung perfusion deficiency. It depends on the effects of anesthetic agents on the cardiopulmonary, cardiovascular, and respiratory systems. In particular, the higher pressure and dose of desflurane supress respiratory system. Oxygen supplementation in general anesthesia increases respiratory rate, but a-2 agonists and ketamine-midazolam effects can eliminate the increasing respiratory rate in general anesthesia.

Differentiating the QRS Morphology of Posterior Fascicular Ventricular Tachycardia From Right Bundle Branch Block and Left Anterior Hemiblock Aberrancy.

Left posterior fascicular ventricular tachycardia (LPF-VT) is frequently misdiagnosed as supraventricular tachycardia with aberrant right bundle branch block (RBBB) and left anterior hemiblock (LAHB). The purpose of the present study was to define the morphological ECG characteristics of LPF-VT and attempt to differentiate it from RBBB and LAHB aberrancy. A systematic Medline search was used to identify or locate ECG tracings from patients with LPF-VTs. ECGs with LPF-VT were also collected from patients who underwent ablation of this arrhythmia at the Tel Aviv and Sheba Medical Centers. These ECGs were compared with ECGs of consecutive patients with RBBB and LAHB and no obvious cardiac pathology by echocardiography. Overall, 183 ECGs of LPF-VT were compared with 61 ECGs showing RBBB and LAHB. Univariate analysis demonstrated differences in QRS axis, limb (I, aVr), and precordial (V1, V2, V6) ECG leads. On multivariate logistic regression analysis, LPF-VT was more often associated with atypical RBBB-like V1 morphology (odds ratio, 5.1; P=0.004), positive QRS in aVr (odds ratio, 19.2; P<0.001), V6 R/S ratio ≤1 (odds ratio, 6.7; P=0.01), and QRS ≤140 ms (odds ratio, 7.7; P<0.001). Using these 4 variables, a prediction model was developed that predicted LPF-VT with sensitivity and specificity of 82.1% and 78.3%, respectively. Patients with 3 of 4 positive variables had high probability of having LPF-VT, whereas patients with ≤1 positive variable always had RBBB plus LAHB. The morphological ECG characteristics of LPF-VT were defined, and a high accurate tool for correctly differentiating LPF-VT from RBBB and LAHB aberrancy was developed.

Association between use of pre-hospital ECG and 30-day mortality: A large cohort study of patients experiencing chest pain

BackgroundIn the assessment of patients with chest pain, there is support for the use of pre-hospital ECG in the literature and in the care guidelines. Using propensity score methods, we aim to examine whether the mere acquisition of a pre-hospital ECG among patients with chest pain affects the outcome (30-day mortality). MethodsThe association between pre-hospital ECG and 30-day mortality was studied in the overall cohort (n=13151), as well as in the one-to-one matched cohort with 2524 patients not examined with pre-hospital ECG and 2524 patients examined with pre-hospital ECG. ResultsIn the overall cohort, 21% (n=2809) did not undergo an ECG tracing in the pre-hospital setting. Among those who had pain during transport, 14% (n=1159) did not undergo a pre-hospital ECG while 32% (n=1135) of those who did not have pain underwent an ECG tracing. In the overall cohort, the OR for 30-day mortality in patients who had a pre-hospital ECG, as compared with those who did not, was 0.63 (95% CI 0.05-0.79; p<0.001). In the matched cohort, the OR was 0.65 (95% CI 0.49-0.85; p<0.001). Using the propensity score, in the overall cohort, the corresponding HR was 0.65 (95% CI 0.58-0.74). ConclusionUsing propensity score methods, we provide real-world data demonstrating that the adjusted risk of death was considerably lower among the cases in whoma pre-hospital ECG was used. The PH-ECG is underused among patients with chest discomfort and the mere acquisition of a pre-hospital ECG may reduce mortality.

Successful use of percussion pacing in a pre-hospital p-wave asystole and ventricular standstill

Background: The use of percussion pacing (PP) using a clenched fist as an external cardiac pacemaker is not scientifically supported. However, European Guidelines for resuscitation 2015 recommend PP as an initial intervention for haemodynamically unstable patients with bradyarrhythmias or p-wave asystole. We describe a case where paramedics witnessed a patient developing p-wave asystole with ventricular standstill, and treated the patient successfully with PP until transcutaneous pacing was established. Case presentation: An 87-year-old man with a previous history of bifascicular heart block collapsed in his private residence in Denmark. Initially conscious and clinically unstable when assessed by Emergency Medical Services (EMS), his condition quickly deteriorated and lost consciousness. PP was initiated resulting in electric capture in shape of broad QRS complexes on the ECG tracing corresponding with palpable carotid pulses and rise in consciousness. The successful intervention lasted for 20 seconds until transcutaneous pacing was commenced and further treatment was established. The patient survived to hospital admission. Conclusions: Although current research has not been able to establish a scientific base for the use of PP in extreme bradycardia and p-wave asystole, several case reports have been published. We contribute to these with our description of an 87-year-old man who benefited from this easy to use and probably life-saving intervention. To our best knowledge, this is the first case report of Danish paramedics intervening with PP.

Performance assessment of dry electrodes for wearable long term cardiac rhythm monitoring: Skin-electrode impedance spectroscopy.

The use of wearable dry sensors for recording long term ECG signals is a requirement for certain studies of heart rhythm. Knowledge of the skin-electrode electrical performance of dry electrodes is necessary when seeking to improve various processing stages for signal quality enhancement. In this paper, methods for the assessment of dry skin-electrode impedance (ZSE) and its modelling are presented. Measurements were carried out on selected electrode materials such as silver, stainless steel, AgCl (dry) and polyurethane. These had ZSE values between 500 kΩ and 1 MΩ within the main ECG frequency range (1 Hz - 100 Hz); in contrast to plain iron material which had a significantly higher impedance. However, in spite of the high ZSE values, open bandwidth ECG traces were of acceptable quality and stability; with dry AgCl material offering the best ECG trace performance.

1301Prognostic value of J (Osborne) waves on ECG tracing during mild therapeutic hypothermia in survivors after out of hospital cardiac arrest (JOW trial)

1301Prognostic value of J (Osborne) waves on ECG tracing during mild therapeutic hypothermia in survivors after out of hospital cardiac arrest (JOW trial)

Screening for Atrial Fibrillation: A Report of the AF-SCREEN International Collaboration.

Approximately 10% of ischemic strokes are associated with atrial fibrillation (AF) first diagnosed at the time of stroke. Detecting asymptomatic AF would provide an opportunity to prevent these strokes by instituting appropriate anticoagulation. The AF-SCREEN international collaboration was formed in September 2015 to promote discussion and research about AF screening as a strategy to reduce stroke and death and to provide advocacy for implementation of country-specific AF screening programs. During 2016, 60 expert members of AF-SCREEN, including physicians, nurses, allied health professionals, health economists, and patient advocates, were invited to prepare sections of a draft document. In August 2016, 51 members met in Rome to discuss the draft document and consider the key points arising from it using a Delphi process. These key points emphasize that screen-detected AF found at a single timepoint or by intermittent ECG recordings over 2 weeks is not a benign condition and, with additional stroke factors, carries sufficient risk of stroke to justify consideration of anticoagulation. With regard to the methods of mass screening, handheld ECG devices have the advantage of providing a verifiable ECG trace that guidelines require for AF diagnosis and would therefore be preferred as screening tools. Certain patient groups, such as those with recent embolic stroke of uncertain source (ESUS), require more intensive monitoring for AF. Settings for screening include various venues in both the community and the clinic, but they must be linked to a pathway for appropriate diagnosis and management for screening to be effective. It is recognized that health resources vary widely between countries and health systems, so the setting for AF screening should be both country- and health system-specific. Based on current knowledge, this white paper provides a strong case for AF screening now while recognizing that large randomized outcomes studies would be helpful to strengthen the evidence base.

Cardiovascular screening in low-income settings using a novel 4-lead smartphone-based electrocardiograph (D-Heart®)

BackgroundMHealth technologies are revolutionizing cardiovascular medicine. However, a low-cost, user-friendly smartphone-based electrocardiograph is still lacking. D-Heart® is a portable device that enables the acquisition of the ECG on multiple leads which streams via Bluetooth to any smartphone. Because of the potential impact of this technology in low-income settings, we determined the accuracy of D-Heart® tracings in the stratification of ECG morphological abnormalities, compared with 12-lead ECGs. MethodsConsecutive African patients referred to the Ziguinchor Regional Hospital (Senegal) were enrolled (n=117; 69 males, age 39±11years). D-Heart® recordings (3 peripheral leads plus V5) were obtained immediately followed by 12 lead ECGs and were assessed blindly by 2 independent observers. Global burden of ECG abnormalities was defined by a semi-quantitative score based on the sum of 9 criteria, identifying four classes of increasing severity. ResultsD-Heart® and 12-lead ECG tracings were respectively classified as: normal: 72 (61%) vs 69 (59%); mildly abnormal: 42 (36%) vs 45 (38%); moderately abnormal: 3 (3%) vs 3 (3%). None had markedly abnormal tracings. Cohen's weighted kappa (kw) test demonstrated a concordance of 0,952 (p<0,001, agreement 98,72%). Concordance was high as well for the Romhilt–Estes score (kw=0,893; p<0,001 agreement 97,35%). PR and QRS intervals comparison with Bland-Altman method showed good accuracy for D-Heart® measurements (95% limit of agreement ±20ms for PR and ±10ms for QRS). ConclusionsD-Heart® proved effective and accurate stratification of ECG abnormalities comparable to the 12-lead electrocardiographs, thereby opening new perspectives for low-cost community cardiovascular screening programs in low-income settings.

Cardiac Mean Electrical Axis in Thoroughbreds-Standardization by the Dubois Lead Positioning System.

BackgroundDifferent methodologies for electrocardiographic acquisition in horses have been used since the first ECG recordings in equines were reported early in the last century. This study aimed to determine the best ECG electrodes positioning method and the most reliable calculation of mean cardiac axis (MEA) in equines.Materials and MethodsWe evaluated the electrocardiographic profile of 53 clinically healthy Thoroughbreds, 38 males and 15 females, with ages ranging 2–7 years old, all reared at the São Paulo Jockey Club, in Brazil. Two ECG tracings were recorded from each animal, one using the Dubois lead positioning system, the second using the base-apex method. QRS complex amplitudes were analyzed to obtain MEA values in the frontal plane for each of the two electrode positioning methods mentioned above, using two calculation approaches, the first by Tilley tables and the second by trigonometric calculation. Results were compared between the two methods.ResultsThere was significant difference in cardiac axis values: MEA obtained by the Tilley tables was +135.1° ± 90.9° vs. -81.1° ± 3.6° (p<0.0001), and by trigonometric calculation it was -15.0° ± 11.3° vs. -79.9° ± 7.4° (p<0.0001), base-apex and Dubois, respectively. Furthermore, Dubois method presented small range of variation without statistical or clinical difference by either calculation mode, while there was a wide variation in the base-apex method.ConclusionDubois improved centralization of the Thoroughbreds' hearts, engendering what seems to be the real frontal plane. By either calculation mode, it was the most reliable methodology to obtain cardiac mean electrical axis in equines.

Modified extradural temporopolar approach with suction decompression for clipping of large paraclinoid aneurysm: Technical note

Background: Cardiovascular diseases (CVD) are considered major health and economic burdens throughout the world. This study was conducted to estimate the magnitude of three major CVD (hypertension, ischemic heart diseases (IHD) and stroke), their risk factors, prevention and, control plan. Methods: The study design was cross-sectional. Multi-stage random sampling technique was used at different schools in Benghazi, Libya. A sample of 1200 teachers was randomly selected. Three formats were used for data collection. These included a self-administered questionnaire, a standardized Rose CVD interview questionnaire, as well as a special form for collecting data on the following: anthropometric measurements, blood pressure, clinical examination, as well as results of laboratory findings, and ECG tracings. Results: The prevalence of hypertension and IHD were 15.1% and 2.7% respectively while no cases of stroke could be detected in the study-sample. The selected CVD were found to be independently predicted by age, gender, family history of hypertension, BMI, smoking index, fasting blood sugar level, and HDL (CI 95%). Conclusion: Risk factors for hypertension & IHD among schoolteachers in Benghazi, Libya included age, BMI, fasting blood sugar, gender, smoking index, HDL, & family history of hypertension. There is thus an urgent need for intensive health education interventions for this group. There is also a need to initiate an implementation of a national program for CVD risk factors assessment, as well as promotion of an overall healthy lifestyle for school teachers through the use of health education which should be directed to smoking health related problems.

Assessment of Autonomic Dysfunction in Acute Stroke Patients at a Tertiary Care Hospital.

In patients who present with acute cerebro-vascular disease, autonomic function testing is usually not given its due importance. This is because of the complex nature of the autonomic function tests and the relative technical difficulty faced in administering the tests to the patients. A simple and non-invasive method to assess the autonomic dysfunction is measurement of resting Heart Rate Variability (HRV). To study the pattern of autonomic dysfunction among patients admitted with acute stroke and to study the relationship between autonomic dysfunction and the morbidity and mortality associated with acute stroke. The study was carried out on 97 patients who were admitted with diagnosis of acute stroke. Patients with conduction abnormalities on ECG were excluded from the study. Resting ECG tracings were obtained for a period of 5 minutes. The frequency domain analysis of HRV was performed by a Fast Fourier transform of the RR intervals. The High Frequency (HF) was representative of the parasympathetic activity while low frequency is representative of baroreceptor mediated parasympathetic and sympathetic activity and Low Frequency (LF)/HF ratio was a measure of the sympathovagal balance. Statistical analysis was carried out with student's t-test and chi-square test and p-value ≥ 0.05 was taken to be statistically significant. The mean age of the patients was 60.84±14.12 years. A total of 41 patients were females and 77 patients had ischemic stroke. Out of the total 97, 60 patients had evidence suggestive of increased sympathetic activity with a mean LF/HF ratio of 2.03±0.88. These patients had significantly higher mean systolic BP, diastolic BP and National Institute of Health Stroke Scale (NIHSS) values when compared to patients with reduced LF/HF ratio (166.33±24.81 vs 148.54±19.42, p=0.0003, 100.33±18.73 vs 88.76±12.66, p=0.0013, 15.77±8.22 vs 11.49±6.63, p=0.0088 respectively). These patients also had a higher mortality rate. This study highlights the problem of autonomic dysfunction among patients with stroke. Patients with autonomic dysfunction had higher morbidity and mortality in the acute phase of stroke in this study and also had higher blood pressure readings. This is a small scale study whose findings need to be validated further by larger population studies.

Point-of-Care Utilisation of Single Lead Smartphone Electrocardiogram in Screening for Arrhythmias: PULSE Trial

Background: AliveCor Heart Rate Monitor (AHM) is an FDA approved hand-held ambulatory cardiac rhythm monitor that records a Lead-I ECG strip when paired with a smartphone. Having demonstrated efficacy in population screening for AF, these devices are marketed to patients as offering medical grade diagnostic capabilities. A paucity of data exists regarding accuracy of clinician interpretation of cardiac rhythm from smartphone-based electrocardiograms. Methods: Patients that underwent cardioversion between July 2016 and January 2017 for AF/atrial flutter were prospectively recruited. Three AHM traces and a 12-lead ECG was recorded- pre and post cardioversion. Two electrophysiologists and general practitioners, blinded to the clinical data, 12-lead-ECG and AHM interpretation assessed each AHM trace independently on an iPhone 6-Plus smartphone. Results: 408 ECG tracings (306 AHM, 102 12-lead ECGs) were recorded from fifty-one patients (mean age 63 ± 14 years). Accuracy of both clinician and automated device diagnosis were compared (Table). Only 2% of AHM tracings were uninterpretable by clinicians as opposed to 15% by the AHM algorithm. Conclusions: Clinician interpretation of a smartphone-based ECG has excellent accuracy for diagnosis of AF but poor sensitivity for diagnosis of atrial flutter. This supports its versatility as a point-of-care device by both cardiologists and GPs in an inpatient or outpatient setting.Tabled 1RhythmElectrophysiologistsGeneral PractitionersAliveCor Auto-Dx(ECG)SensitivitySpecificitySensitivitySpecificitySensitivitySpecificitySinus Rhythm96%88%94%82%78%98%AF87%97%82%91%89%78%A. Flutter28%96%14%82%43%78% Open table in a new tab

The Effect of Exercise on the Timing of Aortic Valve Closure with Respect to the ECG Tracing

Objective: The temporal relationship between electrical repolarization of the heart and mechanical relaxation is not well quantified. In this study we examined the timing of the aortic valve (AoV) closure with respect to the electrical repolarization at rest and following exercise in young healthy subjects. Methods: We measured the period from the apex of the T wave (aT) to the beginning of the second heart sound (S2-aT) and the period from the apex of the T wave to the end of the T wave (eT-aT). Results: At rest, AoV closure occured immediately after the end of the T wave as evidenced by a ratio of (S2-aT)/(eT-aT) greater than 1. The mean time delay between the end of the T wave and AoV closure was 15.5ms which was only 4% of the QT interval duration. After exercise, AoV closure occured just before the end of the T wave (but after the peak of the T wave) as evidenced by the ratio of (S2-aT)/(eT-aT) being between 0 and 1. The mean time difference between the end of the T wave and AoV closure was - 4.4ms, which was only 1% of the QT interval duration. In combination, the QT and RR intervals account for some of the inter-subject variability. Conclusions: AoV closure closely approximates the end of T wave in healthy subjects indicating existence of electromechanical coupling during left ventricular relaxation. Clinically the end of T wave could, therefore, be used as a surrogate for AoV closure in healthy subjects.

Piezoelectric extraction of ECG signal.

The monitoring and early detection of abnormalities or variations in the cardiac cycle functionality are very critical practices and have significant impact on the prevention of heart diseases and their associated complications. Currently, in the field of biomedical engineering, there is a growing need for devices capable of measuring and monitoring a wide range of cardiac cycle parameters continuously, effectively and on a real-time basis using easily accessible and reusable probes. In this paper, the revolutionary generation and extraction of the corresponding ECG signal using a piezoelectric transducer as alternative for the ECG will be discussed. The piezoelectric transducer pick up the vibrations from the heart beats and convert them into electrical output signals. To this end, piezoelectric and signal processing techniques were employed to extract the ECG corresponding signal from the piezoelectric output voltage signal. The measured electrode based and the extracted piezoelectric based ECG traces are well corroborated. Their peaks amplitudes and locations are well aligned with each other.

Automated Data Abstraction of Cardiopulmonary Resuscitation Process Measures for Complete Episodes of Cardiac Arrest Resuscitation.

Cardiopulmonary resuscitation (CPR) process measures research and quality assurance has traditionally been limited to the first 5 minutes of resuscitation due to significant costs in time, resources, and personnel from manual data abstraction. CPR performance may change over time during prolonged resuscitations, which represents a significant knowledge gap. Moreover, currently available commercial software output of CPR process measures are difficult to analyze. The objective was to develop and validate a software program to help automate the abstraction and transfer of CPR process measures data from electronic defibrillators for complete episodes of cardiac arrest resuscitation. We developed a software program to facilitate and help automate CPR data abstraction and transfer from electronic defibrillators for entire resuscitation episodes. Using an intermediary Extensible Markup Language export file, the automated software transfers CPR process measures data (electrocardiogram [ECG] number, CPR start time, number of ventilations, number of chest compressions, compression rate per minute, compression depth per minute, compression fraction, and end-tidal CO2 per minute). We performed an internal validation of the software program on 50 randomly selected cardiac arrest cases with resuscitation durations between 15 and 60 minutes. CPR process measures were manually abstracted and transferred independently by two trained data abstractors and by the automated software program, followed by manual interpretation of raw ECG tracings, treatment interventions, and patient events. Error rates and the time needed for data abstraction, transfer, and interpretation were measured for both manual and automated methods, compared to an additional independent reviewer. A total of 9,826 data points were each abstracted by the two abstractors and by the software program. Manual data abstraction resulted in a total of six errors (0.06%) compared to zero errors by the software program. The mean ± SD time measured per case for manual data abstraction was 20.3 ± 2.7 minutes compared to 5.3 ± 1.4 minutes using the software program (p = 0.003). We developed and validated an automated software program that efficiently abstracts and transfers CPR process measures data from electronic defibrillators for complete cardiac arrest episodes. This software will enable future cardiac arrest studies and quality assurance programs to evaluate the impact of CPR process measures during prolonged resuscitations.