Exercise Electrocardiogram Test Research Articles

Electrocardiogram Testing in Symptomatic Patient with Type-II Diabetes and Left Ventricular Diastolic Dysfunction

Objective: The main objective of the study is to find the exercise electrocardiogram testing in asymptomatic patient with Type-II diabetes and left ventricular diastolic dysfunction. Methods: This descriptive study was conducted in DHQ Hospital, Sheikhupura during January 2019 to November 2019. The data was collected from 50 patients of type II DM. These all patients has normal electrocardiogram (ECG) and normal systolic function. Result: The data was collected from 50 patients of both genders. The mean age of the patients was 47.83±5.61 years. After getting data the results were divided into two parts. There were 25 patients in group A and 25 patients group B. The mean duration of diabetes is 2.5±5.61 years. There were 20 males and 30 females in this data. There were no significant difference of fasting blood sugar in both groups. There was no statically significant difference between two groups regarding left atrial dimension, aortic root dimension, LV end-diastolic dimension, ejection and LV mass. Conclusion: It is concluded that It is concluded that coronary supply route sicknesses is a typical issue in DM, with diastolic brokenness and increment uniquely in patients with positive pressure practice electrocardiography. Keywords: Exercise, Ventricular, Function

SARS-CoV-2 infection and return-to-play in junior competitive athletes: is systematic cardiac screening needed?

Funding AcknowledgementsType of funding sources: None.BackgroundSARS-CoV-2 infection might be associated with cardiac complications in low-risk populations, such as in competitive athletes. However, data obtained in adults cannot be directly transferred to preadolescents and adolescents that are less susceptible to adverse clinical outcomes and are often asymptomatic.PurposeWe conducted this prospective multi-centre study to describe the incidence of cardiovascular complications following SARS-CoV-2 infection in a large cohort of junior athletes and to examine the effectiveness of a screening protocol for a safe return-to-play.MethodsJunior competitive athletes suffering from asymptomatic or mildly symptomatic SARS-CoV-2 infection underwent cardiac screening, including physical examination, 12-lead resting electrocardiogram (ECG), echocardiogram, and exercise ECG testing. Further investigations were performed in cases of abnormal findings.ResultsA total of 571 competitive junior athletes (14.3±2.5 years) were evaluated. About half of the population (50.3%) was mildly symptomatic during SARS-CoV-2 infection, and the average duration of symptoms was 4±1 days. Pericardial involvement was found in 3.2% of junior athletes: small pericardial effusion (2.6%), moderate pericardial effusion (0.2%), and pericarditis (0.4%). No relevant arrhythmias or myocardial inflammation were found in subjects with pericardial involvement. Athletes with pericarditis or moderate pericardial effusion were temporarily disqualified, and a gradual return-to-play was achieved after complete clinical resolution.ConclusionsThe prevalence of cardiac involvement was low in junior athletes after asymptomatic or mild SARS-CoV-2 infection. A screening strategy primarily driven by cardiac symptoms, ECG abnormalities and arrhythmias at rest and/or during exercise should detect cardiac involvement from SARS-CoV-2 infection in most junior athletes. Systematic echocardiographic screening is not recommended in junior athletes.

Exploiting exercise electrocardiography to improve early diagnosis of atrial fibrillation with deep learning neural networks

Atrial fibrillation (AF) is the most common type of sustained arrhythmia. It results from abnormal irregularities in the electrical performance of the atria, and may cause heart thrombosis, stroke, arterial disease, thromboembolism, and heart failure. Prior to the onset of atrial fibrillation, most people experience atrial cardiomyopathy which, if effectively managed, can be prevented from progressing to atrial fibrillation. Electrocardiogram (ECG) can show changes in the heartbeats, and is a common and painless tool to detect heart problems. P-waves in exercise ECGs change more drastically than those in regular ECG, and are more effective in the detection of atrial myocardial diseases. In this paper, we propose a deep learning system to help clinicians to early detect if a patient has atrial enlargement or fibrillation. Firstly, a Convolutional Recurrent Neural Network is employed to locate the P-waves in the patient's exercise ECGs taken in the exercise ECG test process. Relevant parameters are then calculated from the located P-waves. Then a Parallel Bi-directional Long Short-Term Memory Network is applied to analyze the obtained parameters and make a diagnosis for the patient. With our proposed deep learning system, the changes of P-waves collected in different phases in the exercise ECG test can be analyzed simultaneously to get more stable and accurate results. The system can take data of different length as input, and is also applicable to any number of ECG collections. We conduct various experiments to show the effectiveness of our proposed system. We also show that the more ECG data collected in the exercise phase are involved, the more effective our system is in diagnosis of the diseases.

Exercise Electrocardiogram Testing in Asymptomatic Patients with Diabetes and Left Ventricular Diastolic Dysfunction

Objectives: The main objective of the study is to find the exercise electrocardiogram testing in asymptomatic patient with Type-II diabetes and left ventricular diastolic dysfunction.
 Materials and Methods: This descriptive study was conducted Fatima Jinnah Hospital, Lahore during January 2019 to November 2019. The data was collected from 50 patients of type II DM. These all patients has normal electrocardiogram (ECG) and normal systolic function. 
 Results: The data was collected from 50 patients of both genders. The mean age of the patients was 47.83±5.61 years. After getting data the results were divided into two parts. There were 25 patients in group A and 25 patients group B. The mean duration of diabetes is 2.5±5.61 years. There were 20 males and 30 females in this data. There were no significant difference of fasting blood sugar in both groups. There was no statically significant difference between two groups regarding left atrial dimension, aortic root dimension, LV end-diastolic dimension, ejection and LV mass.
 Conclusion: It is concluded that It is concluded that coronary supply route sicknesses is a typical issue in DM, with diastolic brokenness and increment uniquely in patients with positive pressure practice electrocardiography.

Factors for heterogeneous outcomes of angina and myocardial ischemia without obstructive coronary atherosclerosis

The absence of obstructive coronary artery disease (CAD) in patients with angina is common, but its prognosis is debated. We investigated outcomes of such patients to identify predictors of cardiovascular events. We selected 1014 patients with angina, evidence of myocardial ischemia at the electrocardiogram (ECG) exercise test or imaging stress tests, and nonobstructive CAD (absence of lumen diameter reduction ≥50%) at coronary angiography between 1999 and 2015. Note that, 1905 age- and risk factors-matched asymptomatic subjects served as "real-world" comparators. The primary endpoint was the occurrence of all-cause death or myocardial infarction. At 6-years median follow-up (interquartile range, 3-9 years), the primary endpoint occurred in 53 patients (5.5%, 0.92/100 person-years). Besides similar event rates compared with asymptomatic subjects (hazard ratio [HR] 0.85, 95% confidence interval [CI] 0.62-1.15, p = 0.28), the index population showed a very heterogeneous prognosis. Patients with nonobstructive CAD (HR 1.85, 95% CI 1.02-3.37, p = 0.04, compared with "normal" coronary arteries) and ischemia at imaging tests (HR 2.11, 95% CI 1.07-4.14, p = 0.03, compared with ischemia detected only at the ECG exercise test) were at higher risk and those with both these components showing even >10-fold event rates as compared with the absence of both. Three-hundred and twenty-five patients (34%) continued to experience angina, 69 (7.2%) underwent repeat coronary angiography, and 14 (1.5%) had consequent coronary revascularization for atherosclerosis progression. Apart from the impaired quality of life, angina without obstructive CAD has an overall benign but very heterogeneous prognosis. Nonobstructive CAD and myocardial ischemia at imaging tests both confer a higher risk.

Acute electrocardiographic changes during smoking and tobacco chewing: A Cross-sectional study

Background: Smoking increases the risk of coronary artery disease. Very few studies have evaluated the temporal relationship of electrocardiographic changes with smoking. We sought to study and compare the electrocardiogram (ECG) changes during smoking and tobacco chewing in current smokers and tobacco chewers presenting with atypical chest pain with either negative or mild positive exercise ECG test (treadmill test [TMT]). Materials and Methods: We screened male smokers and tobacco chewers with atypical chest pain with TMT. A total of 60 patients, 30 in each group in whom TMT was either negative or mildly positive, underwent a 24-h Holter monitoring. We asked patients to note down their time of smoking and tobacco chewing along with the timing of symptoms if any. Results: All patients were male with an average age of 45 years in smokers and 42 years in the tobacco chewer group. The mean number of cigarettes consumed was 6 ± 2.8 and tobacco chewed was 5 ± 4.7 g/day. Heart rate (HR) in smokers increased from 82.5 ± 14.56/min 10 min before smoking to 90.63 ± 15.34/min, during smoking with peak HR achieved at the time of smoking (P

Exercise electrocardiogram testing in asymptomatic patient with type 2 diabetes and left ventricular diastolic dysfunction

Background: Type 2 diabetes mellitus (DM) is an established risk factor for cardiovascular events and the development of congestive heart failure (HF). Diastolic dysfunction is considered a precursor of HF and may be diagnosed noninvasively by echocardiography. Diastolic dysfunction is common in well-controlled type 2 diabetic patients without clinically detectable heart disease. Left ventricular diastolic dysfunction represents the earliest preclinical dysfunction and that it can progress to asymptomatic HF. Aim of the Work: The aim of the study is to evaluate if diastolic dysfunction in diabetic patients is due to silent ischemia. Methods: This study included 80 asymptomatic patients with type 2 DM. Echocardiography was done to all patients to assess systolic and diastolic functions. Exercise electrocardiogram (ECG) was done for all patients to detect ischemic heart disease. Coronary angiography was done to patients with positive exercise ECG test. Results: The incidence of diastolic dysfunction was 75%; among the studied groups. Impaired relaxation was detected in 87 % and pseudo normal pattern was detected in 13 % of subjects with diastolic dysfunction. Patients with normal diastolic function had negative stress exercise test, while those with diastolic dysfunction, 12 patients had positive exercise stress ECG (40%) and 18 patients had negative exercise stress ECG (60%). Conclusion: These findings indicate that coronary artery disease is not uncommon in diabetic patients with diastolic dysfunction and increase markedly in patients with positive stress exercise electrocardiography.

Prognostic value of electrocardiogram exercise testing for risk stratification in asymptomatic coronary artery disease.

Several variables of electrocardiogram exercise testing (EET) predict cardiovascular events in the general population and in patients with coronary artery disease (CAD). However, most of the studies have not included patients with asymptomatic CAD. The aim of this study was to evaluate the prognostic value of EET in asymptomatic CAD patients. We carried out a retrospective single-center analysis including all patients with asymptomatic CAD documented by angiography who underwent EET from January 2010 to December 2013. A number of EET variables and three exercise scores [Duke Treadmill Score (DTS), Morise score, and FIT score] were analyzed. The primary endpoint was the combined incidence of myocardial infarction (MI), myocardial revascularization, and death from any cause during follow-up. A total of 306 patients were included (mean age was 65±10 years, 61% had previous MI, and the median exercise capacity was 9.4±2.7 metabolic equivalent of task). The primary endpoint occurred in 15.7% of patients during 3.3 years of follow-up. The DTS and FIT were independent predictors of the primary endpoint unlike the Morise score (DTS: hazard ratio=0.91, 95% confidence interval: 0.85-0.99, P=0.018; FIT score: 0.99, 0.98-0.996, P=0.001; Morise score: 0.97, 0.93-1.02, P=0.20). The DTS was independent predictor of MI or revascularization, whereas FIT predicted death from any cause. Excluding patients with early revascularization, DTS had no predictive power at the composite endpoint. In our population with asymptomatic CAD, FIT and DTS had significant value for risk prediction and consequently the EET can be a valid tool in the clinical follow-up of this population.

Long-term prognostic value of peak exercise echocardiogram in patients hospitalized with acute chest pain

Peak exercise echocardiogram (EEcho) has shown reasonable sensitivity and specificity in detecting significant coronary artery disease (CAD). The objective was to evaluate the prognostic value of EEcho in patients hospitalized for acute chest pain (CP) and its additional prognostic information regarding exercise electrocardiogram test (EECG). Prospective observational study performed between May 2011 and September 2013, including 250 patients consecutively admitted for acute CP with normal cardiac biomarkers and nondiagnostic electrocardiogram. All patients were prospectively followed for 1year, and major adverse cardiovascular events (MACE) were recorded: cardiac death, nonfatal myocardial infarction (MI), or angina with coronary revascularization. EEcho was positive in 16%. Patients with positive EEcho had a higher incidence of hypertension and higher TIMI risk score, showing significant CAD in 66%. We observed contradictory results (EECG-EEcho) in 20%. Patients with positive EEcho and negative EECG had significant CAD in the 66%, and patients undergoing coronary angiography with negative EEcho and positive EECG did not show significant coronary artery disease. Only positive EEcho (P<.001, HR 0.169; 95% CI, 0.088-0.250) and atrial fibrillation (P<.025, HR 0.125; 95% CI, 0.016-0.233) were independently associated with MACE during follow-up. In patients with negative EEcho, the presence of MACE was 2%. EEcho in patients hospitalized for acute chest pain presents good ability to diagnose acute coronary syndrome, while providing additional information when combined with an EECG in up to 20% of cases. Moreover, a negative EEcho in this cohort seems to provide prognostic information beyond the acute event to predict long-term MACE.

The value of predischarge exercise ECG testing in chest pain patients in the era of high-sensitivity troponins.

The aim of this study was to examine the value of predischarge exercise electrocardiogram (ECG) testing of chest pain patients in whom acute myocardial infarction (MI) had been ruled out by means of high-sensitivity troponins, ECG and history. All patients hospitalised for chest pain who underwent exercise ECG testing before discharge from the Department of Cardiology, Södersjukhuset, Stockholm, Sweden from January 2011 to June 2012 were included. Endpoints were death, MI and post-discharge revascularisation within 90 and 365 days, respectively. The background one-year risk of death and MI for a corresponding age, gender and calendar time-matched Swedish population was also examined. A total of 951 patients were included. In 585 patients (61.5%) the exercise ECG test was negative, in 94 (9.9%) positive and in 272 (28.6%) inconclusive. There were no significant differences regarding death or MI between patients with a positive or a negative test, neither at 90 ( n=1 (1.1%) vs. n=1 (0.2%)) nor at 365 days ( n=2 (2.1%) vs. n=4 (0.7%)) of follow-up. In total there were nine (0.9%) deaths and 10 (1.1%) MIs within 365 days. The one-year rates of death (1.3%) and MI (0.5%) in a matched Swedish population were comparable. Predischarge exercise ECG testing after rule out of MI did not predict subsequent death or MI in a population of patients hospitalised for chest pain. Furthermore, the risks of death and MI in this population were comparable to a matched Swedish population. These findings suggest that patients could be discharged without this test.

Exercise ECG unmasked Brugada sign: manifestation of the risk of sports-associated sudden cardiac arrest (RCD code: V-1A.1)

Sports‑associated sudden cardiac arrest (SCA) constitutes an important problem. Causes of SCA during sport activities include Brugada syndrome (BrS) among others. We describe a 29‑year‑old male, without a history of cardiovascular disease, who suffered from SCA during football training and despite intensive treatment, after almost 4 weeks of hospitalization, unfortunately died. Detailed medical documentation review showed grade I atrioventricular block, intraventricular conduction abnormalities and BrS type 2 morphology of ST-segment elevation on resting 12‑lead electrocardiogram (ECG). The patient had a history of syncope during physical activity. Further echocardiographic study did not reveal significant structural heart disease. Submaximal exercise testing was performed and showed ventricular extrasystoles during physical activity and type 1 BrS morphology of ST-segment elevation during recovery phase. We compared observed ECG changes to those present in a healthy football player and described noticeable similarities. Exercise ECG testing, especially in patients after syncope of probable arrhythmic etiology, may unmask BrS ECG pattern and lead to BrS diagnosis. JRCD 2017; 3 (3): 92–97.

Screening for asymptomatic coronary artery disease in patients with diabetes mellitus: A systematic review and meta-analysis of randomized trials.

BackgroundScreening diabetic patients for the presence of asymptomatic coronary artery disease (CAD) may potentially impact therapeutic management and outcome. We performed a systematic review and meta-analysis of randomized trials addressing this question.MethodsWe searched the PubMed database for studies reporting a randomized comparison of systematic screening for CAD in diabetic patients versus no systematic screening. The screening protocols were variable with the use of exercise electrocardiogram test, or stress echocardiography, or nuclear test, or coronary computed tomography angiography.ResultsThe final analysis included 5 randomized studies and 3,314 patients altogether. The screening strategy had no detectable impact on outcome with odds ratios (OR) [95 % confidence interval (CI)] of 1.00 [0.67–1.50], 0.72 [0.33–1.57], 0.71 [0.40–1.27], and 0.60 [0.23–1.52] for all-cause death, cardiovascular death, non-fatal myocardial infarction, and the composite cardiovascular death or non-fatal myocardial infarction, respectively. Protocol-related coronary procedures were relatively infrequent in screened patients: coronary angiography was performed in 8 % of the cases, percutaneous coronary intervention in 2.5 %, and coronary artery bypass surgery in 1.5 %. There was no evidence for an effect of screening on the use of statins (OR = 1.19 [0.94–1.51]), aspirin (OR = 1.02 [0.83–1.25]), or angiotensin-converting enzyme inhibitors/angiotensin receptor blockers (OR = 0.97 [0.79–1.19]).ConclusionThe present analysis shows no evidence for a benefit of screening diabetic patients for the presence of asymptomatic CAD. The proportion of patients who undergo myocardial revascularization as a consequence of screening was low.Electronic supplementary materialThe online version of this article (doi:10.1186/s12872-016-0256-9) contains supplementary material, which is available to authorized users.

Exercise left ventricular ejection fraction predicts events in right bundle branch block

ABSTRACT Objective Interpretation of the electrocardiogram (ECG) during exercise is not easy in patients with right bundle branch block (RBBB). Also, the value of exercise echocardiography (ExE) for predicting outcome in them has not been addressed. We sought to assess its prognostic value in patients with RBBB and known/suspected coronary disease. Design Retrospective analysis of data on 703 patients with RBBB who were submitted to a clinically-indicated ExE. The end points were overall mortality and combined myocardial infarction and cardiovascular mortality. Results During follow-up (4.1 ± 4.5 years) there were 130 deaths and 108 combined events. Independent predictors of combined events were history of coronary artery disease (hazard ratio [HR] = 2.37, 95% Confidence Interval [CI] = 1.24–4.52, p = 0.009) resting wall motion score index (HR = 2.14, 95% CI = 1.12–4.10, p = 0.02), metabolic equivalents (HR = 0.89, 95% CI = 0.93–0.97, p = 0.007), Δ in double product with exercise (HR = 0.96, 95% CI = 0.92–1.00, p = 0.036) and Δ in left ventricular ejection fraction (LVEF) with exercise (HR = 0.97, 95% CI = 0.94–0.99, p = 0.01). Neither positive clinical nor ECG exercise testing was predictive. Combined event rates were 3.3% in patients with ΔLVEF > 5%, 4.7% in those with ΔLVEF between 1–5% and 8.2% in those with no increase (Δ < 1%). Conclusions A decrease in LVEF during exercise is predictive of serious events in patients with RBBB.

Development of Non-Invasive Cardiology in Nepal

Nepalese Heart Journal 2015;12(2):61-63.

Utility of the exercise electrocardiogram testing in sudden cardiac death risk stratification.

Sudden cardiac death (SCD) remains a major public health problem. Current established criteria identifying those at risk of sudden arrhythmic death, and likely to benefit from implantable cardioverter defibrillators (ICDs), are neither sensitive nor specific. Exercise electrocardiogram (ECG) testing was traditionally used for information concerning patients' symptoms, exercise capacity, cardiovascular function, myocardial ischemia detection, and hemodynamic responses during activity in patients with hypertrophic cardiomyopathy. We conducted a systematic review of MEDLINE on the utility of exercise ECG testing in SCD risk stratification. Exercise testing can unmask suspected primary electrical diseases in certain patients (catecholaminergic polymorphic ventricular tachycardia or concealed long QT syndrome) and can be effectively utilized to risk stratify patients at an increased (such as early repolarization syndrome and Brugada syndrome) or decreased risk of SCD, such as the loss of preexcitation on exercise testing in asymptomatic Wolff-Parkinson-White syndrome. Exercise ECG testing helps in SCD risk stratification in patients with and without arrhythmogenic hereditary syndromes.

The clinical usefulness of Carotid Ultrasonography in Patients with an Inconclusive Exercise Treadmill Stress Test Result

OP-073 Although an exercise electrocardiogram test is often the first-line screening procedure for subjects with an intermediate probability of coronary artery disease (CAD), one limitation of this test is the high rate of inconclusive tests that result from borderline exercise-induced ST changes.

Exercise electrocardiogram testing in two brothers with different outcome &amp;ndash; a case study exercise testing in master cyclists

The cases of two brothers training and competing as master cyclists and both preparing for a cycling tour are presented. The older brother aged 66 years went first to the primary care physician and presented with an asymptomatic depression in the exercise stress test of the ST segment in V5 and V6 during recovery after complete exhaustion. Coronary angiography revealed a multi vessel coronary artery disease and he underwent bypass surgery. One year later, he successfully completed his planned cycling tour of ~600 km in seven stages and covering ~12,000 m of total ascent. The younger brother aged 59 years went a few months later to the primary care physician and also performed asymptomatic exercise stress testing without changes in the ST segments. Unfortunately, 2 months later he suffered a cardiac arrest during his cycling tour and survived following immediate successful cardiopulmonary resuscitation on the road by his cycling colleagues. Immediate invasive coronary arteriography showed a complete stenosis of the trunk of arteria coronaria sinistra (left coronary artery), a 40%–50% stenosis of ramus circumflexus, and a 20% stenosis of arteria coronaria dextra (right coronary artery). The left coronary artery was dilated and he continued cycling 2 months later. In both brothers, familial hypercholesterolemia was the main cardiovascular risk factor for the multi vessel coronary artery disease. A negative exercise electrocardiogram in siblings with an increased risk for coronary artery disease seemed not to exclude an advanced multi vessel coronary artery disease. In master athletes with asymptomatic exercise electrocardiogram but a positive family history, further examinations should be performed in order to detect relevant stenosis in coronary arteries.

The effects of aerobic exercise on low-and high-density lipoprotein cholesterol

Objective To observe the effects of aerobic exercise on low-and high-density lipoprotein cholesterol,and to investigate the relationship between exercise intensities and high-density lipoprotein cholesterol (HDL-C) changes.Methods Sixty patients with low HDL-C were randomly allocated into a high intensity exercise group,a moderate intensity group or a low intensity group with 20 in each group.According to each patient's maximal heart rate in a restrictive electrocardiogram exercise test,the different aerobic exercise intensities were formulated as follows.The target heart rate of the high-intensity training group was 90％ of each subject's maximum heart rate; in the moderate-intensity group it was 70％ ; in the low-intensity group it was 50％.All 3 groups jogged on a medical treadmill for 20 minutes every other day with their heart rates monitored at all times.They maintained the target heart rate for 20 minutes.The experiment lasted 2 months.Results In the high intensity group HDL-C increased from 0.81 ± 0.22 to 1.04 ± 0.33 mmol/L after training; in the moderate intensity group it increased from 0.82±0.20 to 1.03 ±0.37 mmol/L; in the low intensity group it increased from 0.79 ±0.25 to 0.82 ± 0.27 mmol/L.That increase in the low intensity group was not statistically significant.After high intensity or moderate intensity training the HDL-C increases were statistically significant,but the difference between the groups was not.After training,in 15 cases among the high intensity group,13 cases from moderate intensity group and in 1 case from the low intensity group the HDL-C level achieved a normal value (≥ 1.04 mmol/L).Comparing the high intensity group to the low intensity group or the moderate intensity group to the low intensity group,there were significant differences in the number of patients who achieved normal HDL-C readings,but there was no significant difference between high intensity group and the moderate intensity group.Conclusion Low intensity aerobic exercise has no obvious effect on low HDL-C levels.High or moderate intensity aerobic exercise can effectively raise the HDL-C level,but there is no significant difference in the fraction of patients reaching normal values between high and moderate intensity aerobic exercise.So moderate intensity is recommended for improving low levels of HDL cholesterol. Key words: Aerobic exercise; Exercise intensity; High-density lipoprotein cholesterol

Usefulness of Non-contact Mapping for Radiofrequency Catheter Ablation of Inappropriate Sinus Tachycardia: New Procedural Strategy and Long-term Clinical Outcome

The present study evaluated the clinical benefits of a new therapeutic method of radiofrequency catheter ablation (RFCA) using an EnSite system for inappropriate sinus tachycardia (IST). Six patients with debilitating IST underwent RFCA using EnSite. Using the beta-adrenergic blocker and agonist, the heart rate was controlled between 70 to 150 bpm before and after the RFCA. The areas of the breakout sites (BOSs) were clearly distinguished between those from the normal P-wave zones during rates of less than 100 bpm and those from more upper rate sites during rates of more than 100 bpm using the EnSite system, in accordance with the appearance of tall P-waves (tall P-wave zone) in the IST patients. This was selected as the target for ablation. After the RFCA, the BOSs observed during heart rates of more than 100 bpm moved completely from the tall P-wave zone to the normal P-wave zone in the IST patients. The total number of heart beats and average heart beat on the 24-h Holter monitoring decreased statistically from that before the RFCA to that after, and no adverse heart rate responses was observed after the RFCA. Before the RFCA, the brain natriuretic peptide was elevated, New York Heart Association functional class was worse, and there was an impaired exercise tolerance observed with exercise electrocardiogram testing. The RFCA for the IST significantly improved those parameters. This new therapeutic method for IST using EnSite is effective and produces clinical benefits.

Catecholaminergic Polymorphic Ventricular Tachycardia in a Patient With Recurrent Exertional Syncope

A 16-year-old male with a prior history of recurrent syncope was referred to our hospital after being resuscitated from cardiac arrest developed while playing volleyball. His electrocardiogram (ECG) demonstrated ventricular fibrillation at a local emergency department. After referral, an ECG showed bidirectional ventricular tachycardia (VT) and nonsustained Torsade de Pointes. Two days later, his heart rate became regular, and no additional episodes of VT were observed. His ECG showed sinus rhythm with a corrected QT interval of 423 msec, and two-dimensional echocardiography was unremarkable. We made the diagnosis of a catecholaminergic polymorphic VT. However, only premature ventricular complex bigeminy was induced on exercise ECG and epinephrine infusion tests, and the patient showed no episodes of syncope. His father and mother had different missense mutations in the cardiac ryanodine receptor on genetic testing. The proband had both mutations in different alleles and was symptomatic. It was recommended that the patient avoid competitive physical activities, and a β-blocker was prescribed.