Impact of artificial intelligence arrhythmia mapping on time to first ablation, procedure duration, and fluoroscopy use.

INTRODUCTION: Artificial intelligence (AI) ECG arrhythmia mapping provides arrhythmia source localization using 12-lead ECG data; whether this information impacts procedural efficiency is unknown. We performed a retrospective, case-control study to evaluate the hypothesis that AI ECG mapping may reduce time to ablation, procedural duration, and fluoroscopy. MATERIALS AND METHODS: Cases in which system output was used were retrospectively enrolled according to IRB-approved protocols at each site. Matched control cases were enrolled in reverse chronological order beginning on the last day for which the technology was unavailable. Controls were matched based upon physician, institution, arrhythmia, and a predetermined complexity rating. Procedural metrics, fluoroscopy data, and clinical outcomes were assessed from time-stamped medical records. RESULTS: The study group consisted of 28 patients (age 65 ± 11 years, 46% female, left atrial dimension 4.1 ± 0.9 cm, LVEF 50 ± 18%) and was similar to 28 controls. The most common arrhythmia types were atrial fibrillation (n = 10), premature ventricular complexes (n = 8), and ventricular tachycardia (n = 6). Use of the system was associated with a 19.0% reduction in time to ablation (133 ± 48 vs. 165 ± 49 min, p = 0.02), a 22.6% reduction in procedure duration (233 ± 51 vs. 301 ± 83 min, p < 0.001), and a 43.7% reduction in fluoroscopy (18.7 ± 13.3 vs. 33.2 ± 18.0 min, p < 0.001) versus controls. At 6 months follow-up, arrhythmia-free survival was 73.5% in the study group and 63.3% in the control group (p = 0.56). CONCLUSION: Use of forward-solution AI ECG mapping is associated with reductions in time to first ablation, procedure duration, and fluoroscopy without an adverse impact on procedure outcomes or complications.

POPDC1 Variants Cause Atrioventricular Node Dysfunction and Arrhythmogenic Changes in Cardiac Electrophysiology and Intracellular Calcium Handling in Zebrafish.

Popeye domain-containing (POPDC) proteins selectively bind cAMP and mediate cellular responses to sympathetic nervous system (SNS) stimulation. The first discovered human genetic variant (POPDC1S201F) is associated with atrioventricular (AV) block, which is exacerbated by increased SNS activity. Zebrafish carrying the homologous mutation (popdc1S191F) display a similar phenotype to humans. To investigate the impact of POPDC1 dysfunction on cardiac electrophysiology and intracellular calcium handling, homozygous popdc1S191F and popdc1 knock-out (popdc1KO) zebrafish larvae and adult isolated popdc1S191F hearts were studied by functional fluorescent analysis. It was found that in popdc1S191F and popdc1KO larvae, heart rate (HR), AV delay, action potential (AP) and calcium transient (CaT) upstroke speed, and AP duration were less than in wild-type larvae, whereas CaT duration was greater. SNS stress by ß-adrenergic receptor stimulation with isoproterenol increased HR, lengthened AV delay, slowed AP and CaT upstroke speed, and shortened AP and CaT duration, yet did not result in arrhythmias. In adult popdc1S191F zebrafish hearts, there was a higher incidence of AV block, slower AP upstroke speed, and longer AP duration compared to wild-type hearts, with no differences in CaT. SNS stress increased AV delay and led to further AV block in popdc1S191F hearts while decreasing AP and CaT duration. Overall, we have revealed that arrhythmogenic effects of POPDC1 dysfunction on cardiac electrophysiology and intracellular calcium handling in zebrafish are varied, but already present in early development, and that AV node dysfunction may underlie SNS-induced arrhythmogenesis associated with popdc1 mutation in adults.

In Vivo Cardiac Electrophysiology in Mice: Determination of Atrial and Ventricular Arrhythmic Substrates.

Cardiac arrhythmias are a common cardiac condition that might lead to fatal outcomes. A better understanding of the molecular and cellular basis of arrhythmia mechanisms is necessary for the development of better treatment modalities. To aid these efforts, various mouse models have been developed for studying cardiac arrhythmias. Both genetic and surgical mouse models are commonly used to assess the incidence and mechanisms of arrhythmias. Since spontaneous arrhythmias are uncommon in healthy young mice, intracardiac programmed electrical stimulation (PES) can be performed to assess the susceptibility to pacing-induced arrhythmias and uncover the possible presence of a proarrhythmogenic substrate. This procedure is performed by positioning an octopolar catheter inside the right atrium and ventricle of the heart through the right jugular vein. PES can provide insights into atrial and ventricular electrical activity and reveal whether atrial and/or ventricular arrhythmias are present or can be induced. Here, we explain detailed procedures used to perform this technique, possible troubleshooting scenarios, and methods to interpret the results obtained. © 2024 Wiley Periodicals LLC. Basic Protocol: Programmed electrical stimulation in mice.

Mechanism of Shengmaisan Regulating Cardiac Remodeling of Arrhythmias with Deficiency of Qi and Yin / 中国实验方剂学杂志

Arrhythmia is an important disease among cardiovascular diseases. Malignant arrhythmias often occur clinically and are induced by abnormal ion channels， electrical activity disorders， myocardial fibrosis， inflammation， dysfunctional mitochondrial biogenesis， mitochondrial calcium overload， out-of-balance energy metabolism， oxidative stress， sympathetic hyperactivity， and other pathological cardiac remodeling， and they are the main causes of sudden cardiac death. In traditional Chinese medicine， arrhythmias are considered to be palpitations， which are commonly caused by deficiency of Qi and Yin. It is often manifested as a deficiency of the spleen and stomach， resulting in malfunction of the Qi mechanism， followed by a particularly severe decline in cardiac function. Shengmaisan is a representative formula for nourishing Qi and Yin， consisting of Ginseng Radix et Rhizoma， Ophiopogonis Radix， and Schisandrae Chinensis Fructus. In recent years， clinical studies have shown that Shengmaisan and its additions and subtractions are commonly used in the treatment of arrhythmias. In this article， the mechanisms of the active ingredients of Shengmaisan in the electrophysiology， biochemistry， structure， autonomic nervous system， and subcellular fraction of the heart are reviewed， and the multi-target， multi-system， and integrality of Shengmaisan in the treatment of arrhythmias of Qi and Yin deficiency are described. In addition， energy metabolism disorder is tightly juxtaposed with Qi and Yin deficiency syndrome. Mitochondria， as the center of myocardial energy metabolism， play a paramount role in cardiac remodeling， indicating that Shengmaisan will be a salient part of future research to ameliorate cardiac pathologic remodeling through energy metabolism of mitochondria， so as to provide a theoretical basis for the clinical treatment of these arrhythmias.

Potential proarrhythmic side effect of high dose and prolonged infusion of sodium nitroprusside through calcium ion reduction: a case report.

Background: Sodium nitroprusside (SNP) is an excellent drug in acute decompensated heart failure (HF) patients with high vascular peripheral resistance. Its prolonged administration may cause thiocyanate accumulation and toxicity. A proarrhythmic side effect has never been reported. Case summary: Herein, we report a case of an adult male affected by advanced HF due to a valvular cardiomyopathy admitted to our intensive cardiology unit with severe decompensation and waiting for a heart transplant. He was treated for several weeks with high-dose SNP, due to severe pulmonary hypertension and an extremely labile haemodynamic profile. He progressively developed high thiocyanate levels and, concomitantly, free calcium ion depletion, despite normal total calcium levels, with iterative ventricular arrhythmias. Calcium ion depletion was not responsive to calcium supplementation. We suspected a causative role of thiocyanate since the negatively charged sulfur atom of the thiocyanate molecules could bind the positively charged free calcium ions, leading to a free calcium ion depletion. Thus, we cautiously reduced SNP dosage, according to the patient's haemodynamic profile, with concomitant progressive free calcium ion normalization, thus reducing the arrhythmic burden of the patient, being able to finally perform heart transplantation. Conclusion: We describe for the first time a proarrhythmic side effect of prolonged SNP administration, namely, calcium ion depletion, likely related to thiocyanate toxicity. Despite aggressive calcium supplementation, the only way to reduce the arrhythmic burden was SNP down titration.

Camphor Oil Toxicity: A Case Report.

Camphor is a highly toxic ingredient that can be found in commonly used rubs and preparations such as Tiger balm and Vicks. There is a wide range of symptoms resulting from camphor oil toxicity, manifesting in sweating and agitation and can progress to more serious symptoms of seizures, cardiac arrhythmias, and cardiopulmonary arrest. We present a 61-year-old male, who is a known case of major depressive disorder, was brought to the emergency department on 10/09/2022, two hours after ingesting approximately 500 mL of camphor oil in its liquid form. He developed two episodes of tonic-clonic seizures at home and then later had another episode in the emergency department. As he presented to the emergency room, he was confused, agitated, restless, and diaphoretic. The management in the Emergency Department started with assessing his airway and administration of intravenous (IV) benzodiazepines and IV fluids. The ECG revealed sinus rhythm with borderline QT and QRS. During his stay in the emergency room, his mental status worsened and he became more confused and restless, and he developed another tonic-conic seizure. Therefore, he was intubated. The patient was shifted and managed in the intensive care unit, and 48 hours later the patient was extubated. This case report illustrates the importance of addressing the potential risks of home remedies as they are increasingly being used by the population considering them as safe. Camphor, being the most cultivated essential oil, is a highly toxic compound that, even in very small concentrations, can be lethal to infants and children. It is a component of numerous over-the-counter remedies and has the potential for accidental consumption. Generalized tonic-clonic seizure being the most prominent manifestation which can occur as early as five minutes after exposure needs to be anticipated and treated accordingly. Treatment for symptomatic patients is primarily supportive with special attention paid to QRS complex widening in the ECG.

The Use of Local Activation Timing Histogram in Ablation of Focal and Re-Entrant Atrial Tachycardias.

BACKGROUND: Activation mapping is often used to differentiate focal from re-entrant arrhythmias. This can be challenging but is critical to ablation success. The local activation time (LAT) histogram, which depicts point distribution over isochronal segments, may help characterize arrhythmia mechanisms and identify an optimal ablation strategy. OBJECTIVES: This study aimed to investigate features of the LAT histogram associated with the focal vs re-entrant mechanism of atrial tachycardias (ATs) and the use of the LAT histogram in the identification of target ablation sites. METHODS: We retrospectively evaluated cases of focal and re-entrant ATs performed at a single academic tertiary care center for which activation mapping was performed using CARTO 3 version 7 software (Biosense Webster). Baseline patient, arrhythmia, and procedural characteristics as well as LAT histogram features were evaluated for each case. LAT histogram-guided ablation targets were also compared against actual ablation sites. RESULTS: Among 52 ATs assessed, 17 were focal, and 35 were re-entrant. Tachycardia cycle length was significantly shorter in re-entrant than in focal ATs (288.2 milliseconds [Q1-Q3: 250-306.5 milliseconds] vs 370 milliseconds [Q1-Q3: 285-400 milliseconds], respectively; P = 0.006). LAT histograms contained more "valleys" in re-entrant than in focal ATs (3 [Q1-Q3: 2-4] vs 1 [Q1-Q3: 1-1]; P < 0.001). No focal ATs contained >2 and no re-entrant ATs contained <1 LAT valley(s). All successful ablation sites correlated with LAT histogram-suggested sites. CONCLUSIONS: LAT histograms can help distinguish focal from re-entrant Ats and identify effective ablation sites.

In vivo analysis of acute eletropharmacological effects of proton pump inhibitors using halothane-anesthetized dogs: a translational study of cardiovascular adverse events.

Long-term use of proton pump inhibitors (PPIs) is known to clinically induce hypomagnesemia, increasing the risk toward QT-interval prolongation and lethal ventricular arrhythmias, whereas PPIs can directly modulate cardiac ionic currents in the in vitro experiments. In order to fill the gap between those information, we assessed acute cardiohemodynamic and electrophysiological effects of sub- to supra-therapeutic doses (0.05, 0.5 and 5 mg/kg/10 min) of typical PPIs omeprazole, lansoprazole and rabeprazole, using halothane-anesthetized dogs (n = 6 for each drug). The low and middle doses of omeprazole and lansoprazole increased or tended to increase the heart rate, cardiac output and ventricular contraction, whereas the high dose plateaued and decreased them. Meanwhile, the low and middle doses of omeprazole and lansoprazole decreased the total peripheral vascular resistance, whereas the high dose plateaued and increased it. Rabeprazole decreased the mean blood pressure in a dose-related manner; moreover, its high dose decreased the heart rate and tended to reduce the ventricular contractility. On the other hand, omeprazole prolonged the QRS width. Omeprazole and lansoprazole tended to prolong the QT interval and QTcV, and rabeprazole mildly but significantly prolonged them in a dose-related manner. High dose of each PPI prolonged the ventricular effective refractory period. Omeprazole shortened the terminal repolarization period, whereas lansoprazole and rabeprazole hardly altered it. In effects, PPIs can exert multifarious cardiohemodynamic and electrophysiological actions in vivo, including mild QT-interval prolongation; thus, PPIs should be given with caution to patients with reduced ventricular repolarization reserve.

Small solitary atrial fractionated electrogram zone as a novel ablation target for persistent atrial fibrillation.

INTRODUCTION: Various adjunctive approaches to pulmonary vein isolation (PVI) have been attempted for persistent atrial fibrillation (perAF) and longstanding persistent AF (ls-perAF). We aimed to identify the novel zones responsible for perpetuation of AF. METHODS: To identify novel zones acting as a source of perAF and ls-perAF after PVI/re-PVI, we performed fractionation mapping in 258 consecutive patients with perAF (n = 207) and ls-perAF (n = 51) in whom PVI/re-PVI failed to restore sinus rhythm. RESULTS: In 15 patients with perAF (5.8%: 15/258), fractionation mapping identified a small solitary zone (<1 cm2 ) with high-frequency and irregular waves, showing fractionated electrograms (EGM). We defined this zone as the small solitary atrial fractionated EGM (SAFE) zone. The small SAFE zone was surrounded characteristically by a homogeneous area showing relatively organized activation with nonrapid and nonfractionated waves. Only one small SAFE zone was detected in each patient. This characteristic electrical phenomenon was observed stably during the procedure until ablation. AF duration, (defined as the duration between initial detection of AF and the current ablation) was longer in patients with the small SAFE zone than in those without (median, [25 and 75 percentiles]; 5.0 [3.5, 7.0] vs. 1.1 [1.0, 4.0] years, p = .0008). Longer AF cycle length was observed in patients with the small SAFE zone than in those without. The ablation of the small SAFE zone terminated AF in all 15 patients without any need for other ablations. AF/atrial tachycardia-free rate at follow-up was 93% (14/15) at 6 months, 87% (13/15) at 1 year, and 60% (9/15) at 2 years. CONCLUSIONS: Using fractionation mapping, this study identified a small SAFE zone surrounded characteristically by a homogeneous, relatively organized, low-excitability EGM lesion. The ablation of the small SAFE zone terminated AF in all patients, demonstrating it as a substrate for perpetuated AF. Our findings provide novel ablation targets in perAF patients with prolonged AF duration. Further studies to confirm the present results are warranted.

Review of Case Reports on Adverse Events Related to Pre-workout Supplements Containing Synephrine.

The use of pre-workout supplements has become increasingly popular, including the use of supplements containing synephrine. Synephrine might stimulate weight loss and improve sports performance by its proposed adrenergic properties. However, with its increasing popularity, numerous cases of adverse events related to synephrine use have been reported. This study provides a comprehensive overview and analysis of current case reports related to the supplemental use of synephrine. The scientific literature on cases of adverse events related to synephrine intake was collected through August 2021 using Pubmed and Google Scholar and subsequently reviewed and analysed. We obtained 30 case reports describing a total of 35 patients who suffered from medical complaints following use of synephrine-containing supplements. The patients most often presented with chest pain, palpitations, syncope and dizziness. Commonly raised diagnoses were ischaemic heart disease, cardiac arrhythmias and cerebrovascular disease. Five patients were left disabled or remained on medication at last follow-up. We here show an association between the use of pre-workout supplements containing synephrine and adverse events, mainly related to the cardiovascular system. However, we cannot exclude a role of possible confounding factors such as caffeine. Thus, the use of pre-workout supplements containing synephrine may lead to serious adverse health events, and therefore, caution is needed.

Right ventricular epicardial arrhythmogenic substrate in long-QT syndrome patients at risk of sudden death.

AIMS: The long-QT syndrome (LQTS) represents a leading cause of sudden cardiac death (SCD). The aim of this study was to assess the presence of an underlying electroanatomical arrhythmogenic substrate in high-risk LQTS patients. METHODS AND RESULTS: The present study enrolled 11 consecutive LQTS patients who had experienced frequent implantable cardioverter-defibrillator (ICD discharges triggered by ventricular fibrillation (VF). We acquired electroanatomical biventricular maps of both endo and epicardial regions for all patients and analyzed electrograms sampled from several myocardial regions. Abnormal electrical activities were targeted and eliminated by the means of radiofrequency catheter ablation. VF episodes caused a median of four ICD discharges in eleven patients (6 male, 54.5%; mean age 44.0 ± 7.8 years, range 22-53) prior to our mapping and ablation procedures. The average QTc interval was 500.0 ± 30.2 ms. Endo-epicardial biventricular maps displayed abnormally fragmented, low-voltage (0.9 ± 0.2 mV) and prolonged electrograms (89.9 ± 24.1 ms) exclusively localized in the right ventricular epicardium. We found electrical abnormalities extending over a mean epicardial area of 15.7 ± 3.1 cm2. Catheter ablation of the abnormal epicardial area completely suppressed malignant arrhythmias over a mean 12 months of follow-up (median VF episodes before vs. after ablation, 4 vs. 0; P = 0.003). After the procedure, the QTc interval measured in a 12-lead ECG analysis shortened to a mean of 461.8 ± 23.6 ms (P = 0.004). CONCLUSION: This study reveals that, among high-risk LQTS patients, regions localized in the epicardium of the right ventricle harbour structural electrophysiological abnormalities. Elimination of these abnormal electrical activities successfully prevented malignant ventricular arrhythmia recurrences.

Retrospective Window of Interest Annotation Provides New Insights Into Functional Channels in Ventricular Tachycardia Substrate.

BACKGROUND: Accurate annotation of local activation time is crucial in the functional assessment of ventricular tachycardia (VT) substrate. A major limitation of modern mapping systems is the standard prospective window of interest (sWOI) is limited to 490 to 500 milliseconds, preventing annotation of very late potentials (LPs). A novel retrospective window of interest (rWOI), which allows annotation of all diastolic potentials, was used to assess the functional VT substrate. OBJECTIVES: This study sought to investigate the utility of a novel rWOI, which allows accurate visualization and annotation of all LPs during VT substrate mapping. METHODS: Patients with high-density VT substrate maps and a defined isthmus were included. All electrograms were manually annotated to latest activation using a novel rWOI. Reannotated substrate maps were correlated to critical sites, with areas of late activation examined. Propagation patterns were examined to assess the functional aspects of the VT substrate. RESULTS: Forty-eight cases were identified with 1,820 ± 826 points per map. Using the novel rWOI, 31 maps (65%) demonstrated LPs beyond the sWOI limit. Two distinct patterns of channel activation were seen during substrate mapping: 1) functional block with unidirectional conduction into the channel (76%); and 2) wave front collision within the channel (24%). In addition, a novel marker termed the zone of early and late crowding was studied in the rWOI substrate maps and found to have a higher positive predictive value (85%) than traditional deceleration zones (69%) for detecting critical sites of re-entry. CONCLUSIONS: The standard WOI of contemporary mapping systems is arbitrarily limited and results in important very late potentials being excluded from annotation. Future versions of electroanatomical mapping systems should provide longer WOIs for accurate local activation time annotation.

Predicting human cardiac QT alterations and pro-arrhythmic effects of compounds with a 3D beating heart-on-chip platform.

Determining the potential cardiotoxicity and pro-arrhythmic effects of drug candidates remains one of the most relevant issues in the drug development pipeline (DDP). New methods enabling to perform more representative preclinical in vitro studies by exploiting induced pluripotent stem cell-derived cardiomyocytes (iPSC-CM) are under investigation to increase the translational power of the outcomes. Here we present a pharmacological campaign conducted to evaluate the drug-induced QT alterations and arrhythmic events on uHeart, a 3D miniaturized in vitro model of human myocardium encompassing iPSC-CM and dermal fibroblasts embedded in fibrin. uHeart was mechanically trained resulting in synchronously beating cardiac microtissues in 1 week, characterized by a clear field potential (FP) signal that was recorded by means of an integrated electrical system. A drug screening protocol compliant with the new International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use (ICH) guidelines was established and uHeart was employed for testing the effect of 11 compounds acting on single or multiple cardiac ion channels and well-known to elicit QT prolongation or arrhythmic events in clinics. The alterations of uHeart's electrophysiological parameters such as the beating period, the FP duration, the FP amplitude, and the detection of arrhythmic events prior and after drug administration at incremental doses were effectively analyzed through a custom-developed algorithm. Results demonstrated the ability of uHeart to successfully anticipate clinical outcome and to predict the QT prolongation with a sensitivity of 83.3%, a specificity of 100% and an accuracy of 91.6%. Cardiotoxic concentrations of drugs were notably detected in the range of the clinical highest blood drug concentration (Cmax), qualifying uHeart as a fit-to-purpose preclinical tool for cardiotoxicity studies.

Oxidative stress in the mitochondrial matrix underlies ischemia/reperfusion-induced mitochondrial instability.

Ischemia and reperfusion affect multiple elements of cardiomyocyte electrophysiology, especially within the mitochondria. We previously showed that in cardiac monolayers, upon reperfusion after coverslip-induced ischemia, mitochondrial inner membrane potential (ΔΨ) unstably oscillates between polarized and depolarized states, and ΔΨ instability corresponds with arrhythmias. Here, through confocal microscopy of compartment-specific molecular probes, we investigate the mechanisms underlying the postischemic ΔΨ oscillations, focusing on the role of Ca2+ and oxidative stress. During reperfusion, transient ΔΨ depolarizations occurred concurrently with periods of increased mitochondrial oxidative stress (5.07 ± 1.71 oscillations/15 min, N = 100). Supplementing the antioxidant system with GSH monoethyl ester suppressed ΔΨ oscillations (1.84 ± 1.07 oscillations/15 min, N = 119, t test p = 0.027) with 37% of mitochondrial clusters showing no ΔΨ oscillations (versus 4% in control, odds ratio = 14.08, Fisher's exact test p < 0.001). We found that limiting the production of reactive oxygen species using cyanide inhibited postischemic ΔΨ oscillations (N = 15, t test p < 10-5). Furthermore, ΔΨ oscillations were not associated with any discernable pattern in cell-wide oxidative stress or with the changes in cytosolic or mitochondrial Ca2+. Sustained ΔΨ depolarization followed cytosolic and mitochondrial Ca2+ increase and was associated with increased cell-wide oxidative stress. Collectively, these findings suggest that transient bouts of increased mitochondrial oxidative stress underlie postischemic ΔΨ oscillations, regardless of Ca2+ dynamics.

Predictive value of dynamic electrocardiography for myocardial ischemia and arrhythmia in patients with coronary heart disease / 中国基层医药

Objective:To investigate the predictive value of dynamic electrocardiography (ECG) for myocardial ischemia and arrhythmia in patients with coronary heart disease.Methods:A total of 87 patients with coronary heart disease who received treatment in Wenling Hospital of Traditional Chinese Medicine from January 2020 to January 2022 were included in this study. These patients were divided into a conventional ECG group (group A, n = 40) and a dynamic ECG group (group B, n = 47) according to different examination methods. The detection rate of myocardial ischemia in the two groups was determined. The diagnostic efficacy of routine ECG and dynamic ECG for myocardial ischemia was analyzed according to the results of coronary angiography. The detection rate of arrhythmia was determined in each group. Patient satisfaction was compared between the two groups. Results:There was no significant difference in the total detection rate of myocardial ischemia between the two groups ( P = 0.154). The detection rate of asymptomatic myocardial ischemia in group B [25% (25/47)] was significantly higher than that in group A [10% (10/40), χ2 = 5.24, P = 0.020). According to the results of coronary angiography, the detection rates of myocardial ischemia in group A and group B were 68% (27/40) and 87% (41/47), respectively. The sensitivity, specificity, and accuracy of group B in diagnosing myocardial ischemia were 80% (33/41), [67% (4/6), and 74% (35/47), respectively, all of which were significantly higher than 74% (20/27), [46% (6/13), 68% (27/40) in group A ( χ2 = 8.03, 5.89, 5.03, P = 0.003, 0.012, 0.005). The detection rates of premature ventricular contraction in bi-triplet rhythm, frequent paired premature atrial contraction in bi-triplet rhythm, right bundle-branch block, atrioventricular block, supraventricular tachycardia in group B were significantly higher compared with group A ( χ2 = 10.78, P = 0.001). According to the results of coronary angiography, the detection rates of arrhythmia in groups A and B were 65% (26/40) and 79% (37/47), respectively. The sensitivity, specificity, and accuracy of diagnosing arrhythmia in coronary heart disease in group B were 86% (32/37), 40% (4/10), and 81% (38/47), respectively. The sensitivity and accuracy of diagnosing arrhythmia in coronary heart disease in group B were significantly higher than those in group A [58% (15/26), 55% (22/40), χ2 = 7.30, 4.90, P = 0.005, 0.010). Patient satisfaction in group B [87% (41/47)] was significantly higher than that in group A [65% (26/40), χ2 = 6.24, P = 0.044]. Conclusion:Compared with conventional ECG detection, dynamic ECG has substantially higher detection and diagnosis rates of myocardial ischemia and arrhythmia, as well as a higher patient satisfaction rate, in patients with coronary heart disease, in particular in those with asymptomatic myocardial ischemia.