ECG Measurements Research Articles

The effect of exercise on the ECG criteria for early repolarization pattern

ObjectiveTo determine the effect of exercise and heart rate on the early repolarization (ER) pattern; focusing on the new criteria for identification of ER. MethodsThe ECG measurements on the terminal QRS notch or slur found in early repolarization were quantitated before, during and after exercise; specifically: (i) the amplitude at the onset of the notch (Jo) (ii) the amplitude at the peak of the notch (Jp), (iii) the amplitude at the end of the notch (Jt), (iv) the duration from Jo to Jp (D1) and (v) the duration from Jo to Jt (D2). ResultsAll individuals (N = 21) fulfilling the criteria for ER showed complete disappearance of ER after 3 min of exercise. After 5 min of recovery, 29% of subjects showed return of the ER. The return of ER was dynamic with QRS notching of varying extent, without ST elevation, being evident first. The relationship between heart rate and ER was significant and nonlinear, best fit by a second-order polynomial, suggesting that changes in heart rate with exercise was a factor influencing the presence of the ER pattern and the parameters that define ER. ConclusionEach of the newly defined characteristics of the ER are modified and eventually disappear with exercise. The return of ER was dynamic with QRS notching of varying extent being evident first. The changes correlated with variations in heart rate, during both exercise and recovery, suggesting, in part, a role in the underlying mechanism of ER.

Evaluation of the effects on the QT-interval of 4 artemisinin-based combination therapies with a correction-free and heart rate-free method

Several antimalarial drugs are known to prolong ventricular repolarization as evidenced by QT/QTc interval prolongation. This can lead to Torsades de Pointes, a potentially lethal ventricular arrhythmia. Whether this is the case with artemisinin-based combination therapies (ACTs) remains uncertain. Assessment of the extent of QTc prolongation with antimalarials is hampered by important variations of heart rate during malaria crises and previous studies have reported highly variable values of QTc prolongations with ACTs. We assessed QTc prolongation with four ACTs, using high quality ECG recording and measurement techniques, during the first episode of malaria in 2,091 African patients enrolled in the WANECAM study which also monitored clinical safety. Using an original and robust method of QTc assessment, independent from heart rate changes and from the method of QT correction, we were able to accurately assess the extent of mean maximum QTc prolongation with the four ACTs tested. There was no evidence of proarrhythmia with any treatment during the study although dihydroartemisinin-piperaquine, artesunate-amodiaquine and artemether-lumefantrine significantly prolonged QTc. The extent of prolongation of ventricular repolarization can be accurately assessed in studies where heart rate changes impede QTc assessment.

ECG Biomarker based Heart Disease Automation Detection Scheme

Background/Objectives: With the development of medical technology and the improvement of sanitary environment, human life expectancy has been increasing overcoming fatal diseases, but some diseases still remain as major causes of death. Among them, heart disease is one of the most common causes of death in the world, always in 1st or 2nd place for causes of death. Methods/Statistical analysis: In order to minimize the death from heart disease, prevention and early diagnosis should be done rather than treatment, and in general, ECG measurement can be used to diagnose heart disease. The ECG is a measurement of the electrical signal of the heart using an ECG measuring instrument, which is diagnosed by a specialist, which causes the problem that the patient has to visit the hospital every time. With the recent development of ICT technology, wearable ECG measurement devices are now available for measuring ECG in real life, and by using them it is possible to detect heart disease by measuring ECG without visiting a hospital. Findings: This paper proposes an ECG heart disease detection scheme and infrastructure to diagnose and prescribe heart disease remotely by extracting ECG biomarker from a patient through a wearable ECG measurement device. ECG biomarker can be extracted to provide real-time comparative analysis of heart disease ECG signatures to detect heart disease in an ECG analyzer without the help or expertise of a specialist. Improvements/Applications: Through the proposed ECG biomarker-based heart disease detection scheme and infrastructure, patients and average people can prevent heart disease early and cope with it early.

P.4.06 Treatment with clozapine and olanzapine and cardiac changes in patients with schizophrenia: An MRI study

Antipsychotic use is reported to be associated with a higher risk of sudden cardiac death and new users are especially susceptible to that risk. In this study, we focused on the ability of antipsychotics to prolong the QTc interval at the earliest stages of antipsychotic use. We employed a retrospective cohort study design in a naturalistic setting where having three ECG measurements over time (at baseline and after drug exposure) in antipsychotic-naïve, first-episode schizophrenia (FES) inpatients. The results revealed, in this relatively homogeneous, drug naïve FES patient sample, that QTc intervals were statistically significantly prolongated after a relatively short term (2–4 weeks) of antipsychotic treatments, compared with baseline. After about 2 or 4 weeks of antipsychotic use, the risk of abnormal QTc prolongation was higher than at baseline. These results reinforce the importance of monitoring risk factors and assessing QTc prolongation at the beginning and throughout treatment with antipsychotics.

Monitor a Driver Behavior by ECG Measurement

Monitor a Driver Behavior by ECG Measurement

Влияние динамических характеристик датчиков дыхания на оценку кардиореспираторной синхронизации у больных с заиканием

Various types of sensors are used for assessment of diagnostic indicators based on the analysis of simultaneous measurements of respiration and ECG, such as cardiorespiratory synchronization. One of the most commonly used types of sensors is the thermal sensor, the advantages of which are the simplicity, the possibility to work without specialized masks, which is especially important in otolaryngology since it is often necessary to record speech breathing. The disadvantage of such sensors is the inertia, which should also be taken into consideration in the process of examination. The methods of cardiorespiratory synchronization assessment are sensitive to dynamic characteristics of respiratory sensors. To assess the degree of synchronization methods sensitivity to the dynamic characteristics of sensors is the main objective of this work. In this paper, we study the dynamic characteristics of the respiratory thermal sensor DDT-4-20, most commonly used in medical examinations, and its effect on cardiorespiratory synchronization parameters. An inertialess pressure sensor CJMCU-36 is used as a control device. The authors compare the cardiorespiratory synchronization indicators calculated by simultaneous measurements of inertial thermal sensor DDT-4-20 and inertialess pressure sensor CJMCU-36. It has been found that the inertia of the tested sensor slightly violates the synchronization ratio, the effect of the sensor inertia on the number and length of the inspiratory chains is more significant.

The relationship between p wave dispersion and left atrial volume index in patients with metabolic syndrome

Aim: The incidence of cardiovascular diseases has increased in patients with metabolic syndrome(MS)and left atrial functions also begin to deteriorate from the early period. This effect could be demonstrated by both ECG and Echocardiography. In this study, we investigated the relationship between left atrium volume index (LAVi), which is a sensitive indicator of left atrial dysfunction, and p-wave dispersion (Pd) in patients with MS. Material and Methods: Patients with MS were included in the study. Baseline ECG and transthoracic echocardiography (TTE) measurements were performed and the correlation between the Pd and LAVi was investigated. Results: 180 patients were included in the study. The median age of the study population was45(36-57) and 64% was male. In correlation analysis, there was a good correlation between Pd and LAVi(r:0.73 and p

Measurement of capacitive coupled ECG from the car seat

Abstract The topic of the article is the design and construction of the device for measurement of ECG in the car. This device is divided into two parts: sensing part and processing part. These parts are described in detail in separated sections. The sensing part of the device was incorporated into the driver’s seat. The ECG signal is measured through capacitive coupled electrodes installed in the seat that includes high-input impedance amplifier and sensing electrode surface. This sensing part of the device is capable of recording electrocardiogram data through clothing. Part of the hardware responsible for processing of the recorded signal was placed out of the seat and it is connected through shielded cable with sensing electrodes in order to reduce noise. The main part of the hardware dealing with signal digitalization and filtration utilizes analog front-end ADS1191 by Texas Instrument. It is possible to set up sampling frequency, gain of channel and configuration of RLD circuit during data acquisition. The experimental measurement and ability of the device to measure capacitive coupled ECG while driving are presented at the end of the article.

Analysis of effect of antidepressant drug venlafaxine on length of QT interval in patients with depressive disorder and alcohol dependence

<p>Introduction. Depressive disorder is common in patients with the diagnosis of alcoholism. Comorbidity of depression and alcoholism significantly worsens the clinical status of patients and represents a major therapeutic challenge. The aim of the study was to investigate the effect of the antidepressant drug venlafaxine on the length of QT interval in patients with depressive disorder and alcohol dependence. Methods. The research included 49 male patients (>18 years of age) with alcohol dependence, who were also diagnosed with depressive disorder by using DSM-IV criterion and positive Hamilton Rating Scale for Depression (HRSD) at the very beginning of hospitalization. The patients had been given 37.5 mg of the antidepressant drug venlafaxine twice a day for twenty days. The global QTc interval (12 leads) was determined automatically using ECG device Schiller Cardiovit AT-1, which used "SCHILLER ECG Measurement and Interpretation Software for Children and Adult ECGs". Statistical data processing was performed using SPSS 16.0 programme package for Windows. Results. There was a statistically significant positive association between HRSD score (depression intensity) and the serum levels of creatine kinase isoenzyme MB, i.e. the degree of myocardial damage (p = 0.048). A statistically significant positive correlation between serum gamma-glutamyltransferase levels and the length of QTc interval (p < 0.001) was also found. There was no statistically significant difference in the length of QTc interval before and after venlafaxine administration (p = 0.827), and the average prolongation of the QTc interval was 0.776 ms (95% CI = -6.323 ms-7.874 ms). Conclusion. In our study, we did not prove the negative effect of antidepressant drug venlafaxine on QT interval in patients with depressive disorder and alcohol dependence. In patients with alcohol dependence, the therapy for depression must have a priority due to the proven negative association between depression and the degree of myocardial damage.</p>

Analiza dejstva antidepresivnog leka sertralina na dužinu QT intervala kod depresivnih pacijenata sa alkoholnom zavisnošću

Introduction and Aim: Depression in psychiatry covers a large area of mental pathology and it is one of the most complex problems of modern medicine with broad implications for the health of the individual and the society as a whole. Depression is also a frequent companion of alcohol addiction. The aim of this study was to investigate the effect of the antidepressant drug sertraline on the length of QT interval in depressed patients with alcohol dependence. Patients and methods: This research included male patients (older than 18 years of age) suffering from alcohol addiction, who were also diagnosed with depression, that is, depressive disorder, at the beginning of hospitalisation, on the basis of DSM-IV (Diagnostic and statistical manual of mental disorders) criterion and positive Hamilton Rating Scale for Depression (HRSD). The study included 49 patients treated with antidepressant sertraline for 20 days. In our study, the global QTc interval (12 leads) was determined automatically by applying ECG device of the producer and type "Schiller Cardiovit AT-1", which uses "SCHILLER ECG Measurement and Interpretation Software for Children and Adult ECGs". Measured/empirical values of data were statistically processed in SPSS 16.0 programme package for Windows. Methods of descriptive statistics and methods of statistic testing of hypotheses were used. Results: In our study, in spite of the vulnerability of patients due to the heart damage and the liver dysfunction arising from alcohol consumption, as well as altered patients' drugs metabolism, no elongation of QTc interval resulting from the application of sertraline was established (p = 0.735). The average prolongation of QTc interval of 1.633 ms was observed (95% CI = 8.005 ms, 11.270 ms). Conclusion: Our study does not indicate that the antidepressant drug sertraline has a statistically significant effect on the prolongation of the QT interval of depressed patients with alcohol dependence.

Bioequivalence of 2 Naproxen Sodium Tablet Formulations in Healthy Male and Female Volunteers

Naproxen is an established, effective treatment for pain management in acute musculoskeletal disorders and traumatic sports injuries. Reckitt Benckiser Health Limited have developed a naproxen sodium tablet with the same pharmacokinetic and pharmacodynamic properties as existing marketed naproxen products with the intention of increasing the number of naproxen products available for prescribers and pharmacies. This study aimed to assess comparative bioavailability between a test medicinal product developed by Reckitt Benckiser Health Limited (RB, 103-105 Bath Rd, Slough, SL1 3UH, United Kingdom; RB naproxen sodium 220 mg tablets), and a reference medicinal product, Aleve naproxen sodium 220 mg (Bayer B.V., Energieweg 1, 3641 RT Mijdrecht, Netherlands), in the fasted state. This was a randomized, single-dose, 2-way crossover, open-label, comparative bioavailability, pharmacokinetic study in 18 healthy male and female volunteers with a 5- to 8-day washout permitted between doses (based on the anticipated minimum washout period for naproxen determined from the known terminal elimination half-life of up to 17 hours). Blood samples were taken periodically over a 72-hour period following dosing and analyzed for plasma naproxen concentration using a validated LC-MS method. Noncompartmental pharmacokinetic analysis was used to derive pharmacokinetic parameters for naproxen; safety and tolerability were evaluated throughout the study. Following a single-dose administration of naproxen sodium tablets (2 × 220 mg), the Cmax and AUC0-t (geometric least squares mean) for the test product was 65.88 µg/mL and 893.37 h * µg/mL, respectively; and for the reference product was 64.59 µg/mL and 890.60 h * µg/mL. The geometric least squares mean test/reference ratio 90% CI for both Cmax (93.98-110.70) and AUC0-t (98.04-102.63) was contained entirely within the predefined 80.00% to 125.00% lower and upper limits; additionally, there was no statistically significant difference in Tmax (P = 0.9878) following fasted administration of the test and reference product. There was 1 treatment-emergent adverse event reported during the study; there were no serious adverse events, no suspected unexpected serious adverse events, and no clinically significant changes in laboratory safety, vital signs, or 12-lead ECG measurements reported. This single-dose study found that the test product (RB naproxen sodium tablets) and reference product (Aleve naproxen sodium tablets) met the regulatory criteria for bioequivalence in these fasted male and female volunteers; both test and reference products were found to be safe and well tolerated.

The Reproducibility of Global Electrical Heterogeneity ECG Measurements.

Global electrical heterogeneity (GEH) is a useful predictor of adverse clinical outcomes. However, reproducibility of GEH measurements on 10-second routine clinical ECG is unknown. Data of the prospective cohort study of incident hemodialysis patients (n=253; mean age 54.6±13.5y; 56% male; 79% African American) were analysed. Two random 10-second segments of 5-minute ECG recording in sinus rhythm were compared. GEH was measured as spatial QRS-T angle, spatial ventricular gradient (SVG) magnitude and direction (azimuth and elevation), and a scalar value of SVG measured by (1) sum absolute QRST integral (SAI QRST), and (2) QT integral on vector magnitude signal (iVMQT). Bland-Altman analysis was used to calculate agreement. For all studied vectorcardiographic metrics, agreement was substantial (Lin's concordance coefficient >0.98), and precision was perfect (>99.99%). 95% limits of agreement were ±14° for spatial QRS-T angle, ±13° for SVG azimuth, ±4° for SVG elevation, ±14 mV*ms for SVG magnitude, and ±17 mV*ms for SAI QRST. SAI QRST and iVMQT were in substantial agreement with each other. Reproducibility of a 10-second automated GEH ECG measurements was substantial, and precision was perfect.

Myocardial Ischemia Detection from Slope of ECG ST Segment

Myocardial ischemia occurs when blood flow to heart is reduced preventing it from receiving enough oxygen. It is a possible indication of partial or complete blockage of coronary arteries. Though ischemia is accompanied by symptoms (fatigue, chest pain, shortness of breath etc.) sometimes it can be silent. If not treated, it can lead to various heart diseases. Most importantly it can progress to myocardial infarction (heart attack), which can be fatal. Thus detecting ischemia at an early stage is important to prevent serious implications. Nowadays personal healthcare monitoring systems are used which provide vital physiological information. In future ECG measurement devices would also be common in homes. So, the proposed work intends to develop an algorithm in detecting myocardial ischemia from ECG, which would be computationally less complex and easy to implement in homecare ECG devices. One way to do it is through continuous or long term monitoring of ECG. The ST segment elevation (or depression) indicates presence of ischemia. The proposed method measures slope of ST segment which must vary in case of ST changes. The algorithm is tested on selected records of the European ST-T database and returns an accuracy of 83.33%.Bangladesh Journal of Medical Physics Vol.10 No.1 2017 12-24

First real-world experience with mobile health telemonitoring in adult patients with congenital heart disease.

BackgroundArrhythmias and heart failure are common and invalidating sequelae in adult patients with congenital heart disease (CHD). Mobile health (m-Health) enables daily monitoring and a timely response that might prevent deterioration. We present an observational prospective registry to evaluate feasibility of an m‑Health telemonitoring program for managing arrhythmia, heart failure and blood pressure in symptomatic adults with CHD.MethodsSymptomatic adult patients with CHD are enrolled in an m‑Health telemonitoring program, which evaluates single-lead ECG, blood pressure and weight measurements. In case of symptoms extra measurements could be performed. Data are collected by mobile apps, matched with individualised thresholds. Patients are contacted if thresholds were exceeded or if arrhythmias were found, for treatment adjustments or reassurance. Data on emergency care utilisation, hospitalisation and patient-reported outcome measures are used to assess quality of life and self-management.Results129 symptomatic CHD patients were invited to participate, 55 participated. Reasons for refusing consent included too time consuming to participate in research (30) and to monitor vital signs (14). At baseline 22 patients were in New York Heart Association class ≥ II heart failure, 43 patients had palpitations or documented arrhythmias, and 8 had hypertension. Mean follow-up was 3.0 months, one patient dropped out, and adherence was 97%.ConclusionThe first results indicate that this program is feasible with high adherence.

Primary Effect of SERCA 2a Gene Transfer on Conduction Reserve in Chronic Myocardial Infarction.

Background SERCA2a gene transfer (GT) improves mechano‐electrical function in animal models of nonischemic heart failure Whether SERCA2a GT reverses pre‐established remodeling at an advanced stage of ischemic heart failure is unclear. We sought to uncover the electrophysiological effects of adeno‐associated virus serotype 1.SERCA2a GT following myocardial infarction (MI).Methods and ResultsPigs developed mechanical dysfunction 1 month after anterior MI, at which point they received intracoronary adeno‐associated virus serotype 1.SERCA2a (MI+SERCA2a) or saline (MI) and were maintained for 2 months. Age‐matched naive pigs served as controls (Control). In vivo ECG‐and‐hemodynamic properties were assessed before and after dobutamine stress. The electrophysiological substrate was measured using optical action potential (AP) mapping in controls, MI, and MI+SERCA2a preparations. In vivo ECG measurements revealed comparable QT durations between groups. In contrast, prolonged QRS duration and increased frequency of R′ waves were present in MI but not MI+SERCA2a pigs relative to controls. SERCA2a GT reduced in in vivo arrhythmias in response to dobutamine. Ex vivo preparations from MI but not MI+SERCA2a or control pigs were prone to pacing‐induced ventricular tachycardia and fibrillation. Underlying these arrhythmias was pronounced conduction velocity slowing in MI versus MI+SERCA2a at elevated rates leading to ventricular tachycardia and fibrillation. Reduced susceptibility to ventricular tachycardia and fibrillation in MI+SERCA2a pigs was not related to hemodynamic function, contractile reserve, fibrosis, or the expression of Cx43 and Nav1.5. Rather, SERCA2a GT decreased phosphoactive CAMKII‐delta levels by >50%, leading to improved excitability at fast rates.Conclusions SERCA2a GT increases conduction velocity reserve, likely by preventing CAMKII overactivation. Our findings suggest a primary effect of SERCA2a GT on myocardial excitability, independent of altered mechanical function.

Caffeine, gravity, and baroreceptor function: the integration of diet and cardiovascular control.

We describe a simple, cost-effective experiment to demonstrate cardiovascular integration of heart rate and blood pressure to accommodate the environmental and dietary factors of gravity and caffeine. Specific learning objectives associated with this include understanding the effects of posture on blood pressure and heart rate, coupled with the role of caffeine in modifying this response. Inclusion of ECG measurements, coupled with heart rate variability analysis, added a demonstration of the contribution made by the autonomic nervous system under these conditions. We clearly demonstrate that the cardiac work, estimated as rate-pressure product, necessary to undertake the transition from supine to standing, is fixed for a given group of subjects. However, the individual contribution of heart rate and systolic pressure to the cardiac workload is subject to the external factors of gravity and caffeine. Such an activity also demonstrates additional benefits, including unstructured teaching opportunities to augment classroom learning associated with integrative physiology and also the discussion of ethical issues with regard to human experimentation.

Respiratory-Induced Hemodynamic Changes Measured by Whole-Body Multichannel Impedance Plethysmography

The cardiovascular system is described by parameters including blood flow, blood distribution, blood pressure, heart rate and pulse wave velocity. Dynamic changes and mutual interactions of these parameters are important for understanding the physiological mechanisms in the cardiovascular system. The main objective of this study is to introduce a new technique based on parallel continuous bioimpedance measurements on different parts of the body along with continuous blood pressure, ECG and heart sound measurement during deep and spontaneous breathing to describe interactions of cardiovascular parameters. Our analysis of 30 healthy young adults shows surprisingly strong deep-breathing linkage of blood distribution in the legs, arms, neck and thorax. We also show that pulse wave velocity is affected by deep breathing differently in the abdominal aorta and extremities. Spontaneous breathing does not induce significant changes in cardiovascular parameters.

Noninvasive predictors of cardiac arrhythmias in bodybuilders

Introduction and ObjectiveArrhythmias are often recorded in strength training athletes without cardiovascular abnormalities but may also be a sign of an underlying cardiovascular disease which carries a risk of sudden cardiac death (SCD). Nowadays, bodybuilding is a popular sport among adolescents and young adults. There have been few studies of arrhythmias comparing bodybuilders with healthy controls and excluding anabolic steroid use. We aimed to assess the structural, functional and electrical characteristics of bodybuilders’ hearts compared with control subjects. MethodsIn this study, we assessed 35 male competitive bodybuilders and 35 healthy control subjects matched for age, gender, and body mass index. A detailed cardiovascular and systemic examination was performed at the beginning of the study to collect demographic data and anthropometric measures. Biochemical and hematologic, echocardiographic, 24-h Holter, and ECG measurements were obtained from all participants. ResultsVentricular arrhythmias were encountered significantly more frequently in bodybuilders than in the control group. QT and QTc were not significantly different between groups. Tp-e interval, Tp-e/QT ratio, and Tp-e/QTc ratio were significantly greater in bodybuilders than in the control group (p<0.001 for all). There was a positive correlation between Tp-e interval, Tp-e/QT ratio, and Tp-e/QTc ratio and right ventricular (RV) diameter and arrhythmias. ConclusionProlonged repolarization is common in athletes, although its predictive value is unclear. In this study, alterations in ventricular repolarization were positively correlated with RV dimensions. Therefore, we postulate that arrhythmias in strength athletes may be predicted by assessing the right ventricle echocardiographically and dispersions of repolarization on the ECG, and that SCD could be avoided in strength athletes by careful application of this information.

Heart Rate Variability Analysis on CEBS Database Signals.

Heart rate variability (HRV) is a valuable noninvasive tool of assessing the state of cardiovascular autonomic function. Over the recent years there has been interest in heart rate monitoring without electrodes. Seismocardiography (SCG) is a non-invasive technique of recording and analyzing cardiovascular vibrations. The purpose of this study is to compare HRV indices calculated on SCG and ECG signals from Combined measurement of ECG, breathing and seismocardiogram (CEBS) database. The authors use 20 signals lasting 200 s acquired from patients in supine position and compare heart rate variability parameters from the seismocardiogram and ECG reference signal. They assessed the performance of heart beat detector on SCG channel. The results of modified version of SCG heart beat detection prove its good performance on signals with higher sampling frequency. Strong linear correlation of HRV indices calculated from ECG and SCG prove the reliability of SCG in HRV analysis performed on signals from CEBS Database.

The influences of the M2R-GIRK4-RGS6 dependent parasympathetic pathway on electrophysiological properties of the mouse heart.

A large body of work has established the prominent roles of the atrial M2R-IKACh signaling pathway, and the negative regulatory protein RGS6, in modulating critical aspects of parasympathetic influence on cardiac function, including pace-making, heart rate (HR) variability (HRV), and atrial arrhythmogenesis. Despite increasing evidence of its innervation of the ventricles, and the expression of M2R, IKACh channel subunits, and RGS6 in ventricle, the effects of parasympathetic modulation on ventricular electrophysiology are less clear. The main objective of our study was to investigate the contribution of M2R-IKACh signaling pathway elements in murine ventricular electrophysiology, using in-vivo ECG measurements, isolated whole-heart optical mapping and constitutive knockout mice lacking IKACh (Girk4–/–) or RGS6 (Rgs6-/-). Consistent with previous findings, mice lacking GIRK4 exhibited diminished HR and HRV responses to the cholinergic agonist carbachol (CCh), and resistance to CCh-induced arrhythmic episodes. In line with its role as a negative regulator of atrial M2R-IKACh signaling, loss of RGS6 correlated with a mild resting bradycardia, enhanced HR and HRV responses to CCh, and increased propensity for arrhythmic episodes. Interestingly, ventricles from mice lacking GIRK4 or RGS6 both exhibited increased action potential duration (APD) at baseline, and APD was prolonged by CCh across all genotypes. Similarly, CCh significantly increased the slope of APD restitution in all genotypes. There was no impact of genotype or CCh on either conduction velocity or heterogeneity. Our data suggests that altered parasympathetic signaling through the M2R-IKACh pathway can affect ventricular electrophysiological properties distinct from its influence on atrial physiology.