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International Journal of Cardiology Dec 2003Conversion of atrial fibrillation and flutter to sinus rhythm results in a transient mechanical dysfunction of atrium and atrial appendage, termed atrial stunning.... (Review)
Review
Conversion of atrial fibrillation and flutter to sinus rhythm results in a transient mechanical dysfunction of atrium and atrial appendage, termed atrial stunning. Atrial stunning has been reported with all modes of conversion of atrial fibrillation and flutter to sinus rhythm including both transthoracic and low energy internal electrical, pharmacological, and spontaneous cardioversion, and conversion by overdrive pacing and by radiofrequency ablation. Atrial stunning is a function of the underlying arrhythmia becoming apparent at the restoration of sinus rhythm, not the function of the mode of conversion, and does not develop after the unsuccessful attempts of cardioversion or the delivery of electric current to the heart during rhythms other than atrial fibrillation or flutter. Tachycardia-induced atrial cardiomyopathy, cytosolic calcium accumulation, and atrial hibernation are the suggested mechanisms of atrial stunning. Atrial stunning is at maximum immediately after cardioversion and improves progressively with a complete resolution within a few minutes to 4-6 weeks depending on the duration of the preceding atrial fibrillation, atrial size, and structural heart disease. Atrial stunning causes postcardioversion thromboembolism despite restoration of sinus rhythm. Duration of anticoagulation therapy after successful cardioversion should depend on the duration of atrial stunning. Lack of improvement in cardiac output and functional recovery of patients immediately after cardioversion is attributed to the atrial stunning. Verapamil, acetylstrophenathidine, isoproterenol, and dofetilide have been reported to protect from atrial stunning in animal and small human studies. Right atrium stunning is less marked and improves earlier than that of left atrium, resulting in a differential atrial stunning explaining the rare occurrence of pulmonary edema after cardioversion.
Topics: Animals; Anti-Arrhythmia Agents; Atrial Fibrillation; Atrial Flutter; Atrial Function; Atrial Function, Left; Atrial Function, Right; Catheter Ablation; Electric Countershock; Humans; Isoproterenol; Myocardial Stunning; Phenethylamines; Sotalol; Sulfonamides; Thromboembolism; Time Factors; Verapamil
PubMed: 14659842
DOI: 10.1016/s0167-5273(03)00107-4 -
Journal of Cardiovascular... Aug 2022A 47-year-old man with symptomatic paroxysmal atrial fibrillation (AF) underwent AF ablation. Activation maps during right atrial pacing and sinus rhythm before the...
A 47-year-old man with symptomatic paroxysmal atrial fibrillation (AF) underwent AF ablation. Activation maps during right atrial pacing and sinus rhythm before the ablation revealed distinctive left atrial (LA) propagations with multiple LA breakthrough sites via epicardial connections. A wide area circumferential ablation was not able to achieve a right pulmonary vein (RPV) isolation and required an inner PV ablation to isolate the RPV. Activation maps during different rhythms before the ablation may be helpful to unmask multiple epicardial connections between the RPV and right atrium.
Topics: Atrial Appendage; Atrial Fibrillation; Catheter Ablation; Heart Atria; Humans; Male; Middle Aged; Pulmonary Veins
PubMed: 35775820
DOI: 10.1111/jce.15619 -
Frontiers in Physiology 2020Circadian rhythms are involved in many physiological and pathological processes in different tissues, including the heart. Circadian rhythms play a critical role in... (Review)
Review
Circadian rhythms are involved in many physiological and pathological processes in different tissues, including the heart. Circadian rhythms play a critical role in adverse cardiac function with implications for heart failure and sudden cardiac death, highlighting a significant contribution of circadian mechanisms to normal sinus rhythm in health and disease. Cardiac arrhythmias are a leading cause of morbidity and mortality in patients with heart failure and likely cause ∼250,000 deaths annually in the United States alone; however, the molecular mechanisms are poorly understood. This suggests the need to improve our current understanding of the underlying molecular mechanisms that increase vulnerability to arrhythmias. Obesity and its associated pathologies, including diabetes, have emerged as dangerous disease conditions that predispose to adverse cardiac electrical remodeling leading to fatal arrhythmias. The increasing epidemic of obesity and diabetes suggests vulnerability to arrhythmias will remain high in patients. An important objective would be to identify novel and unappreciated cellular mechanisms or signaling pathways that modulate obesity and/or diabetes. In this review we discuss circadian rhythms control of metabolic and environmental cues, cardiac ion channels, and mechanisms that predispose to supraventricular and ventricular arrhythmias including hormonal signaling and the autonomic nervous system, and how understanding their functional interplay may help to inform the development and optimization of effective clinical and therapeutic interventions with implications for chronotherapy.
PubMed: 33519516
DOI: 10.3389/fphys.2020.611860 -
Frontiers in Psychology 2020Pulmonary ventilation and respiration are considered to be primarily involved in oxygenation of blood for oxygen delivery to cells throughout the body for metabolic... (Review)
Review
Pulmonary ventilation and respiration are considered to be primarily involved in oxygenation of blood for oxygen delivery to cells throughout the body for metabolic purposes. Other pulmonary physiological observations, such as respiratory sinus arrhythmia, Hering Brewer reflex, cardiorespiratory synchronization, and the heart rate variability (HRV) relationship with breathing rhythm, lack complete explanations of physiological/functional significance. The spectrum of waveforms of breathing activity correlate to anxiety, depression, anger, stress, and other positive and negative emotions. Respiratory pattern has been thought not only to be influenced by emotion but to itself influence emotion in a bi-directional relationship between the body and the mind. In order to show how filling in gaps in understanding could lead to certain future developments in mind-body medicine, biofeedback, and personal health monitoring, we review and discuss empirical work and tracings to express the vital role of bodily rhythms in influencing emotion, autonomic nervous system activity, and even general neural activity. Future developments in measurement and psychophysiological understanding of the pattern of breathing in combination with other parameters such as HRV, cardiorespiratory synchronization, and skin conductivity may allow for biometric monitoring systems to one day accurately predict affective state and even affective disorders such as anxiety. Better affective prediction based on recent research when incorporated into personal health monitoring devices could greatly improve public mental health by providing at-home biofeedback for greater understanding of one's mental state and for mind-body affective treatments such as breathing exercises.
PubMed: 32922338
DOI: 10.3389/fpsyg.2020.01980 -
IEEE Transactions on Bio-medical... Apr 2011Automatic detection of atrial fibrillation (AF) for AF diagnosis, especially for AF monitoring, is necessarily desirable for clinical therapy. In this study, we proposed...
Automatic detection of atrial fibrillation (AF) for AF diagnosis, especially for AF monitoring, is necessarily desirable for clinical therapy. In this study, we proposed a novel method for detection of the transition between AF and sinus rhythm based on RR intervals. First, we obtained the delta RR interval distribution difference curve from the density histogram of delta RR intervals, and then detected its peaks, which represented the AF events. Once an AF event was detected, four successive steps were used to classify its type, and thus, determine the boundary of AF: 1) histogram analysis; 2) standard deviation analysis; 3) numbering aberrant rhythms recognition; and 4) Kolmogorov-Smirnov (K-S) test. A dataset of 24-h Holter ECG recordings (n = 433) and two MIT-BIH databases (MIT-BIH AF database and MIT-BIH normal sinus rhythm (NSR) database) were used for development and evaluation. Using the receiver operating characteristic curves for determining the threshold of the K-S test, we have achieved the highest performance of sensitivity and specificity (SP) (96.1% and 98.1%, respectively) for the MIT-BIH AF database, compared with other previously published algorithms. The SP was 97.9% for the MIT-BIH NSR database.
Topics: Algorithms; Atrial Fibrillation; Diagnosis, Computer-Assisted; Electrocardiography; Humans; Pattern Recognition, Automated; Reproducibility of Results; Sensitivity and Specificity
PubMed: 21134807
DOI: 10.1109/TBME.2010.2096506 -
Journal of Arrhythmia Jun 2022Electrocardiogram (ECG) interpretation is an integral part of the clinical ECG workflow; however, this process is often time-consuming and labor-intensive. We aim to...
BACKGROUND
Electrocardiogram (ECG) interpretation is an integral part of the clinical ECG workflow; however, this process is often time-consuming and labor-intensive. We aim to develop a rapid, inexpensive means to detect abnormal ECGs using artificial intelligence (AI) from scanned ECG printouts.
METHODS
The study included 1172 12-lead ECG scans performed in 1172 individuals from a community in Guangzhou, China; 878 (74.9%) were diagnosed with sinus rhythm, and the remaining 294 (25.1%) with abnormal rhythms. A deep learning model consisting of a convolutional neural network based on InceptionV3 and a fully connected layer followed by a GEV activation was trained to classify scanned tracings as either normal or abnormal.
RESULTS
In a hold-out testing set, the model achieved a area under curve (AUC), sensitivity, specificity, PPV, and NPV of 0.932 (95% confidence interval [CI]: 0.890, 0.976), 0.816 (95% CI: 0.657, 0.923), 0.993 (95% CI: 0.959, 1.0), 0.969 (95% CI: 0.838, 0.999), and 0.950 (95% CI: 0.90, 0.980) respectively, when using a probability threshold of 0.5. When compared with a physiological expert, these results show comparable performance with a statistically significant increase in specificity and a non-significant decrease in sensitivity at the 95% level.
CONCLUSIONS
We have developed a rapid, inexpensive, accurate means to detect abnormal ECGs using AI. Easy and accurate identification of such "abnormal" ECGs could allow the mass automated review of ECGs in community settings where abnormal ones could be flagged using AI for detailed clinical review by healthcare professionals.
PubMed: 35785392
DOI: 10.1002/joa3.12707 -
Advanced Emergency Nursing JournalA 63-year-old man presented to the emergency department for fluttering in the chest. The initial electrocardiogram (ECG) suggested rapid atrial fibrillation with...
A 63-year-old man presented to the emergency department for fluttering in the chest. The initial electrocardiogram (ECG) suggested rapid atrial fibrillation with nonspecific RS- and ST-segment abnormalities. Treatment with intravenous β-blocker resulted in conversion to a normal sinus rhythm. The repeat ECG revealed conversion to normal sinus rhythm with an inferior lateral myocardial infarction. This case presentation identifies the importance of an algorithmic approach to identifying narrow complex tachyarrhythmias considering both cardiac and noncardiac causes. Furthermore, evaluating ECG changes when varying rates and rhythms exist on differing ECGs. Identifying the importance of serial ECGs is emphasized by the case presented, concluding with an understanding of arrhythmias associated with myocardial infarctions and clinical pearls.
Topics: Atrial Fibrillation; Diagnosis, Differential; Electrocardiography; Emergency Service, Hospital; Humans; Male; Middle Aged; Myocardial Infarction
PubMed: 33915564
DOI: 10.1097/TME.0000000000000343 -
American Journal of Veterinary Research May 2024To investigate whether pulse-wave analysis (PWA) performed by trained evaluators facilitates detection of nonsinus rhythm.
OBJECTIVE
To investigate whether pulse-wave analysis (PWA) performed by trained evaluators facilitates detection of nonsinus rhythm.
ANIMALS
Same-day, high-definition oscillometry pulse-wave data and ECG results of 155 animals (144 dogs and 11 cats) were analyzed.
METHODS
In this cross-sectional study, we enrolled 18 participants from various backgrounds, all of whom received PWA training. The ability to distinguish between sinus and nonsinus rhythms was assessed using receiver operating characteristic curve analysis. The pulse-wave datasets were divided into 5 ECG categories. Agreement between ECG diagnoses and PWA-based arrhythmia detection was evaluated using Cohen κ values, and the correlation between the academic year of veterinary students and their κ values was assessed.
RESULTS
All cardiology researchers demonstrated satisfactory accuracy in distinguishing pathological rhythms using PWA (area under the curve, 0.704 to 0.761), with the highest accuracy in detecting atrial fibrillation (area under the curve, 0.811 to 0.845). Fair agreement with ECG categorization was achieved by all 3 cardiology researchers, 2 of 5 general practitioners, and 3 of 10 veterinary undergraduates. The veterinary undergraduates' years of study were correlated with their diagnostic performance (Spearman ρ = 0.658; P = .019).
CLINICAL RELEVANCE
PWA during routine noninvasive blood pressure measurement showed significant potential for the detection of pathological arrhythmias, notably atrial fibrillation. This approach yielded improved effectiveness when it was used by veterinarians with cardiology experience. Thus, introducing hands-on training courses, particularly those focused on cardiology and interactive workshops, may enable frontline veterinarians to promptly identify arrhythmias using PWA, facilitating timely ECG examinations or referrals.
Topics: Animals; Cross-Sectional Studies; Electrocardiography; Dogs; Cats; Dog Diseases; Pulse Wave Analysis; Arrhythmias, Cardiac; Cat Diseases; Blood Pressure Determination; Humans; Female; Blood Pressure; Male
PubMed: 38422616
DOI: 10.2460/ajvr.23.10.0233 -
Heart and Vessels Sep 2016Catheter tissue contact force (CF) is an important factor for durable lesion formation during radiofrequency catheter ablation (RFCA) of atrial fibrillation (AF). Since... (Comparative Study)
Comparative Study
Atrial rhythm influences catheter tissue contact during radiofrequency catheter ablation of atrial fibrillation: comparison of contact force between sinus rhythm and atrial fibrillation.
Catheter tissue contact force (CF) is an important factor for durable lesion formation during radiofrequency catheter ablation (RFCA) of atrial fibrillation (AF). Since CF varies in the beating heart, atrial rhythm during RFCA may influence CF. A high-density map and RFCA points were obtained in 25 patients undergoing RFCA of AF using a CF-sensing catheter (Tacticath, St. Jude Medical). The operators were blinded to the CF information. Contact type was classified into three categories: constant, variable, and intermittent contact. Average CF and contact type were analyzed according to atrial rhythm (SR vs. AF) and anatomical location. A total of 1364 points (891 points during SR and 473 points during AF) were analyzed. Average CFs showed no significant difference between SR (17.2 ± 11.3 g) and AF (17.2 ± 13.3 g; p = 0.99). The distribution of points with an average CF of ≥20 and <10 g also showed no significant difference. However, the distribution of excessive CF (CF ≥40 g) was significantly higher during AF (7.4 %) in comparison with SR (4.2 %; p < 0.05). At the anterior area of the right inferior pulmonary vein (RIPV), the average CF during AF was significantly higher than during SR (p < 0.05). Constant contact was significantly higher during AF (32.2 %) when compared to SR (9.9 %; p < 0.01). Although the average CF was not different between atrial rhythms, constant contact was more often achievable during AF than it was during SR. However, excessive CF also seems to occur more frequently during AF especially at the anterior part of RIPV.
Topics: Action Potentials; Aged; Atrial Fibrillation; Cardiac Catheters; Catheter Ablation; Equipment Design; Female; Heart Rate; Humans; Male; Middle Aged; Prospective Studies; Pulmonary Veins; Transducers, Pressure; Treatment Outcome
PubMed: 26498938
DOI: 10.1007/s00380-015-0763-0 -
Entropy (Basel, Switzerland) Sep 2020It is known that in pathological conditions, physiological systems develop changes in the multiscale properties of physiological signals. However, in real life, little...
It is known that in pathological conditions, physiological systems develop changes in the multiscale properties of physiological signals. However, in real life, little is known about how changes in the function of one of the two coupled physiological systems induce changes in function of the other one, especially on their multiscale behavior. Hence, in this work we aimed to examine the complexity of cardio-respiratory coupled systems control using multiscale entropy (MSE) analysis of cardiac intervals MSE (RR), respiratory time series MSE (Resp), and synchrony of these rhythms by cross multiscale entropy (CMSE) analysis, in the heart failure (HF) patients and healthy subjects. We analyzed 20 min of synchronously recorded RR intervals and respiratory signal during relaxation in the supine position in 42 heart failure patients and 14 control healthy subjects. Heart failure group was divided into three subgroups, according to the RR interval time series characteristics (atrial fibrillation (HFAF), sinus rhythm (HFSin), and sinus rhythm with ventricular extrasystoles (HFVES)). Compared with healthy control subjects, alterations in respiratory signal properties were observed in patients from the HFSin and HFVES groups. Further, mean MSE curves of RR intervals and respiratory signal were not statistically different only in the HFSin group ( = 0.43). The level of synchrony between these time series was significantly higher in HFSin and HFVES patients than in control subjects and HFAF patients ( < 0.01). In conclusion, depending on the specific pathologies, primary alterations in the regularity of cardiac rhythm resulted in changes in the regularity of the respiratory rhythm, as well as in the level of their asynchrony.
PubMed: 33286811
DOI: 10.3390/e22091042