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IEEE Transactions on Bio-medical... Jan 2019An accurate rhythm analysis during cardiopulmonary resuscitation (CPR) would contribute to increase the survival from out-of-hospital cardiac arrest. Piston-driven...
GOAL
An accurate rhythm analysis during cardiopulmonary resuscitation (CPR) would contribute to increase the survival from out-of-hospital cardiac arrest. Piston-driven mechanical compression devices are frequently used to deliver CPR. The objective of this paper was to design a method to accurately diagnose the rhythm during compressions delivered by a piston-driven device.
METHODS
Data was gathered from 230 out-of-hospital cardiac arrest patients treated with the LUCAS 2 mechanical CPR device. The dataset comprised 201 shockable and 844 nonshockable ECG segments, whereof 270 were asystole (AS) and 574 organized rhythm (OR). A multistage algorithm (MSA) was designed, which included two artifact filters based on a recursive least squares algorithm, a rhythm analysis algorithm from a commercial defibrillator, and an ECG-slope-based rhythm classifier. Data was partitioned randomly and patient-wise into training (60%) and test (40%) for optimization and validation, and statistically meaningful results were obtained repeating the process 500 times.
RESULTS
The mean (standard deviation) sensitivity (SE) for shockable rhythms, specificity (SP) for nonshockable rhythms, and the total accuracy of the MSA solution were: 91.7 (6.0), 98.1 (1.1), and 96.9 (0.9), respectively. The SP for AS and OR were 98.0 (1.7) and 98.1 (1.4), respectively.
CONCLUSIONS
The SE/SP were above the 90%/95% values recommended by the American Heart Association for shockable and nonshockable rhythms other than sinus rhythm, respectively.
SIGNIFICANCE
It is possible to accurately diagnose the rhythm during mechanical chest compressions and the results considerably improve those obtained by previous algorithms.
Topics: Algorithms; Artifacts; Cardiopulmonary Resuscitation; Electrocardiography; Humans; Out-of-Hospital Cardiac Arrest; Sensitivity and Specificity; Signal Processing, Computer-Assisted
PubMed: 29993407
DOI: 10.1109/TBME.2018.2827304 -
Journal of Community Hospital Internal... 2018The term 'flutter' and 'fibrillation' were first coined to differentiate the differences between fast, regular contractions in Atrial Flutter (AFLUT) with irregular,... (Review)
Review
The term 'flutter' and 'fibrillation' were first coined to differentiate the differences between fast, regular contractions in Atrial Flutter (AFLUT) with irregular, vermiform contractions of Atrial Fibrillation (AFIB). Management of these two diseases has been a challenge for physicians. Rate control (along with rhythm control) is the first line of management for symptomatic AFIB/AFLUT with Rapid Ventricular Rate (RVR). In some situations, atrial rhythms may not be well controlled by these anti-arrhythmic drugs, making cardioversion to sinus rhythm necessary. Anti-coagulation therapy in both the disease population is essential. Catheter ablation is an effective treatment option in certain patients that have AFIB/AFLUT refractory to medical management. Newer techniques like left atrial appendage (LAA) has been developed and is a highly attractive concept for the future in the management of AFIB/AFLUT. Newer novel drugs targeting specific ion channels are approaching the stages of clinical investigation. However, while advances in technologies have helped elucidate many aspects of these diseases, many mysteries still remain. This literature review serves as one of the guideline papers for current up-to-date management on both AFIB and AFLUT.
PubMed: 30357020
DOI: 10.1080/20009666.2018.1514932 -
Poincaré Plot Image and Rhythm-Specific Atlas for Atrial Bigeminy and Atrial Fibrillation Detection.IEEE Journal of Biomedical and Health... Apr 2021A detector based only on RR intervals capable of classifying other tachyarrhythmias in addition to atrial fibrillation (AF) could improve cardiac monitoring. In this...
A detector based only on RR intervals capable of classifying other tachyarrhythmias in addition to atrial fibrillation (AF) could improve cardiac monitoring. In this paper a new classification method based in a 2D non-linear RRI dynamics representation is presented. For this aim, the concepts of Poincaré Images and Atlases are introduced. Three cardiac rhythms were targeted: Normal sinus rhythm (NSR), AF and atrial bigeminy (AB). Three Physionet open source databases were used. Poincaré Images were generated for all signals using different Poincaré plot configurations: RR, dRR and RRdRR. The study was computed for different time window lengths and bin sizes. For each rhythm, the Poincaré Images of the 80% of that rhythm's patients were used to create a reference image, a Poincaré Atlas. The remaining 20% were used as test set and classified into one of the three rhythms using normalized mutual information and 2D correlation. The process was iterated in a tenfold cross-validation and patient-wise dataset division. Sensitivity results obtained for RRdRR configuration and bin size 40 ms, for a 60 s time window were 94.35% ±3.68, 82.07% ±9.18 and 88.86% ±12.79 with a specificity of 85.52% ±7.46, 95.91% ±3.14, 96.10% ±2.25 for AF, NSR and AB respectively. Results suggest that a rhythms general RRI pattern may be captured using Poincaré Atlases and that these can be used to classify other signal segments using Poincaré Images. In contrast with other studies, the former method could be generalized to more cardiac rhythms and does not depend on rhythm-specific thresholds.
Topics: Algorithms; Atrial Fibrillation; Databases, Factual; Electrocardiography; Heart Rate; Humans; Monitoring, Physiologic
PubMed: 32750972
DOI: 10.1109/JBHI.2020.3012339 -
Clinical Cardiology Oct 2019Despite the technical improvements made in recent years, the overall long-term success rate of ventricular tachycardia (VT) ablation in patients with ischemic... (Review)
Review
Despite the technical improvements made in recent years, the overall long-term success rate of ventricular tachycardia (VT) ablation in patients with ischemic cardiomyopathy remains disappointing. This unsatisfactory situation has persisted even though several approaches to VT substrate ablation allow mapping and ablation of noninducible/nontolerated arrhythmias. The current substrate mapping methods present some shortcomings regarding the accurate definition of the true scar, the modality of detection in sinus rhythm of abnormal electrograms that identify sites of critical channels during VT and the possibility to determine the boundaries of functional re-entrant circuits during sinus or paced rhythms. In this review, we focus on current and proposed ablation strategies for VT to provide an overview of the potential/real application (and results) of several ablation approaches and future perspectives.
Topics: Body Surface Potential Mapping; Catheter Ablation; Heart Conduction System; Humans; Myocardial Ischemia; Prognosis; Tachycardia, Ventricular
PubMed: 31411347
DOI: 10.1002/clc.23245 -
Prenatal Diagnosis Dec 2004We intend to review our experience with the investigation and management of foetal arrhythmia on the basis of superior vena cava/ascending aorta (SVC/AA) Doppler flow... (Review)
Review
We intend to review our experience with the investigation and management of foetal arrhythmia on the basis of superior vena cava/ascending aorta (SVC/AA) Doppler flow velocity recordings. Irregular rhythms n = 307. Premature atrial and ventricular contractions were easily identified and generally self-limited in time. Sustained bradycardia n = 19. Four had sinus bradycardia, six presented with blocked atrial bigeminism, three showed 2:1, and five had a complete atrio-ventricular (AV) block. Another foetus that presented with first-degree AV block developed a Luciani-Wenckebach phenomenon 1 week later. These different types of bradycardia were all identified on SVC/AA Doppler recordings. Tachyarrhythmia n = 30. Five types of tachyarrhythmia were observed: Type I: Short ventriculo-atrial (VA) tachycardia (VA < AV), n = 11. Ten foetuses of this group presented a distinctive Doppler flow velocity pattern characterised by 1:1 AV conduction and a tall atrial wave ('a' wave) superimposed on the aortic ejection wave. They were considered to have re-entrant tachycardia through a fast-conducting AV accessory pathway; all 10 responded to digoxin therapy. The eleventh foetus with short VA tachycardia had atrial ectopic tachycardia with AV node dysfunction; he was treated successfully with sotalol. Type II: Long VA tachycardia (VA > AV): n = 8. In seven cases, an 'a' wave of normal amplitude with normal AV time interval could be clearly identified in front of the aortic ejection wave: one foetus in this group was considered to be in sinus tachycardia based on the variability of its heart rate; in another, sudden onset of tachycardia triggered by extrasystoles led to the possibility of permanent junctional reciprocating tachycardia (PJRT). The five other foetuses had atrial ectopic tachycardia. The last foetus presented with AV and VA intervals of the same duration and a heart rate of 210 beats/min; he did not respond either to digoxin or to sotalol, and was found after birth to have PJRT. The drug of first choice in this group was sotalol. Type III: Simultaneous onset of atrial and ventricular contractions: n = 3. These foetuses were classified as junctional ectopic tachycardia. Two responded to amiodarone. The other foetus converted spontaneously to sinus rhythm. Type IV: Flutter: n = 7. All presented with 2:1 AV relationship except one who had a variable block. Digoxin was prescribed as a first choice associated with sotalol in three cases. Conversion to sinus rhythm was documented in all; however, one hydropic foetus with advanced cardiomyopathy died one day after birth. Type V: Ventricular tachycardia: n = 1. This 30-week foetus presented alternance of AV dissociation (atrial rate: 130, ventricular rate: 170 beats/min) and atrial capture (ventricular rate of 138 beats/min). The arrhythmia responded well to propanol, and no recurrence was recorded after birth. Precise prenatal identification of arrhythmia type can be achieved with the SVC/AA Doppler approach. Such information allows for a better management and a rational choice of appropriate anti-arrhythmic drug.
Topics: Arrhythmias, Cardiac; Bradycardia; Echocardiography, Doppler; Fetal Diseases; Humans; Tachycardia; Ultrasonography, Prenatal
PubMed: 15612055
DOI: 10.1002/pd.1064 -
Journal of Electrocardiology 2012Systems providing computer-based analysis of the resting electrocardiogram (ECG) seek to improve the quality of health care by providing accurate and timely automatic... (Comparative Study)
Comparative Study
BACKGROUND
Systems providing computer-based analysis of the resting electrocardiogram (ECG) seek to improve the quality of health care by providing accurate and timely automatic diagnosis of, for example, cardiac rhythm to clinicians. The accuracy of these diagnoses, however, remains questionable.
OBJECTIVES
We tested the hypothesis that (a) 2 independent automated ECG systems have better accuracy in rhythm diagnosis than nonexpert clinicians and (b) both systems provide correct diagnostic suggestions in a large percentage of cases where the diagnosis of nonexpert clinicians is incorrect.
METHODS
Five hundred ECGs were manually analyzed by 2 senior experts, 3 nonexpert clinicians, and automatically by 2 automated systems. The accuracy of the nonexpert rhythm statements was compared with the accuracy of each system statement. The proportion of rhythm statements when the clinician's diagnoses were incorrect and the systems instead provided correct diagnosis was assessed.
RESULTS
A total of 420 sinus rhythms and 156 rhythm disturbances were recognized by expert reading. Significance of the difference in accuracy between nonexperts and systems was P = .45 for system A and P = .11 for system B. The percentage of correct automated diagnoses in cases when the clinician was incorrect was 28% ± 10% for system A and 25% ± 11% for system B (P = .09).
CONCLUSION
The rhythm diagnoses of automated systems did not reach better average accuracy than those of nonexpert readings. The computer diagnosis of rhythm can be incorrect in cases where the clinicians fail in reaching the correct ECG diagnosis.
Topics: Automation; Chi-Square Distribution; Clinical Competence; Diagnosis, Computer-Assisted; Diagnostic Errors; Electrocardiography; Female; Humans; Male; Middle Aged; Signal Processing, Computer-Assisted
PubMed: 21816409
DOI: 10.1016/j.jelectrocard.2011.05.007 -
Heart Rhythm May 2021Heart rate follows a diurnal variation, and slow heart rhythms occur primarily at night.
BACKGROUND
Heart rate follows a diurnal variation, and slow heart rhythms occur primarily at night.
OBJECTIVE
The lower heart rate during sleep is assumed to be neural in origin, but here we tested whether a day-night difference in intrinsic pacemaking is involved.
METHODS
In vivo and in vitro electrocardiographic recordings, vagotomy, transgenics, quantitative polymerase chain reaction, Western blotting, immunohistochemistry, patch clamp, reporter bioluminescence recordings, and chromatin immunoprecipitation were used.
RESULTS
The day-night difference in the average heart rate of mice was independent of fluctuations in average locomotor activity and persisted under pharmacological, surgical, and transgenic interruption of autonomic input to the heart. Spontaneous beating rate of isolated (ie, denervated) sinus node (SN) preparations exhibited a day-night rhythm concomitant with rhythmic messenger RNA expression of ion channels including hyperpolarization-activated cyclic nucleotide-gated potassium channel 4 (HCN4). In vitro studies demonstrated 24-hour rhythms in the human HCN4 promoter and the corresponding funny current. The day-night heart rate difference in mice was abolished by HCN block, both in vivo and in the isolated SN. Rhythmic expression of canonical circadian clock transcription factors, for example, Brain and muscle ARNT-Like 1 (BMAL1) and Cryptochrome (CRY) was identified in the SN and disruption of the local clock (by cardiomyocyte-specific knockout of Bmal1) abolished the day-night difference in Hcn4 and intrinsic heart rate. Chromatin immunoprecipitation revealed specific BMAL1 binding sites on Hcn4, linking the local clock with intrinsic rate control.
CONCLUSION
The circadian variation in heart rate involves SN local clock-dependent Hcn4 rhythmicity. Data reveal a novel regulator of heart rate and mechanistic insight into bradycardia during sleep.
Topics: Animals; Bradycardia; Circadian Clocks; Disease Models, Animal; Electrocardiography; Gene Expression Regulation; Hyperpolarization-Activated Cyclic Nucleotide-Gated Channels; Mice; RNA; Sinoatrial Node
PubMed: 33278629
DOI: 10.1016/j.hrthm.2020.11.026 -
Journal of the American College of... Dec 1999The left atrial (LA) appendage is a common source of cardiac thrombus formation associated with systemic embolism. Transesophageal echocardiography allows a detailed... (Review)
Review
The left atrial (LA) appendage is a common source of cardiac thrombus formation associated with systemic embolism. Transesophageal echocardiography allows a detailed evaluation of the structure and function of the appendage by two-dimensional imaging and Doppler interrogation of appendage flow. Specific flow patterns, reflecting appendage function, have been characterized for normal sinus rhythm and various abnormal cardiac rhythms. Appendage dysfunction has been associated with LA appendage spontaneous echocardiographic contrast, thrombus formation and thromboembolism. These associations have been studied extensively in patients with atrial fibrillation or atrial flutter, in patients undergoing cardioversion of atrial arrhythmias and in patients with mitral valve disease. The present review summarizes the literature on the echocardiographic assessment of LA appendage structure, function and dysfunction, which has become an integral part of the routine clinical transesophageal echocardiographic examination.
Topics: Atrial Appendage; Atrial Fibrillation; Atrial Flutter; Atrial Function; Blood Flow Velocity; Echocardiography, Doppler; Echocardiography, Transesophageal; Heart Diseases; Heart Rate; Humans; Predictive Value of Tests; Thrombosis
PubMed: 10588196
DOI: 10.1016/s0735-1097(99)00472-6 -
Heart (British Cardiac Society) May 1998To determine the clinical and electrophysiological characteristics of patients with paroxysmal palpitations and neck pounding during sinus rhythm.
OBJECTIVE
To determine the clinical and electrophysiological characteristics of patients with paroxysmal palpitations and neck pounding during sinus rhythm.
METHODS
Clinical, electrocardiographic, and electrophysiological characteristics of six patients with paroxysmal palpitations and neck pounding during sinus rhythm were studied in basal conditions and when symptomatic. Response to treatment was observed.
RESULTS
Baseline ECGs were normal (four patients) or had first degree atrioventricular block with intermittent PR shortening. During symptoms, narrow QRS rhythms were seen without visible P waves (three patients) or with P waves partially hidden in the QRS complex (three patients). Dual atrioventricular nodal pathways were found in all five patients who had electrophysiological studies. In these patients the slow pathway conduction time was long enough (mean (SD), 425 (121) ms) for ventricular activation after slow pathway conduction during sinus rhythm to coincide with the next atrial depolarisation, causing neck pounding during exercise (four patients) or at rest (two patients). Tachycardia was not induced in any patient. Medical treatment aggravated symptoms in three patients. A pacemaker was successfully used in two.
CONCLUSIONS
Neck pounding during sinus rhythm is a clinical manifestation of dual atrioventricular nodal pathways. Medical treatment may aggravate symptoms but a pacemaker may offer definitive relief.
Topics: Adult; Atrioventricular Node; Electrocardiography; Female; Humans; Jugular Veins; Male; Tachycardia, Paroxysmal
PubMed: 9659197
DOI: 10.1136/hrt.79.5.490 -
Annals of Emergency Medicine Sep 1984Electromechanical dissociation (EMD) implies organized electrical depolarization of the heart without synchronous myocardial fiber shortening and, therefore, without...
Electromechanical dissociation (EMD) implies organized electrical depolarization of the heart without synchronous myocardial fiber shortening and, therefore, without cardiac output. Experimentally EMD can be produced by inducing ventricular fibrillation, not performing cardiopulmonary resuscitation, and applying a defibrillating shock after a few minutes. The result is frequently the restoration of electrical activity of the heart; however, because of diffuse myocardial ischemia, there is no mechanical contraction. The simultaneous electrocardiogram and arterial pressure tracings can reveal a variety of organized ECG rhythms (sinus rhythm, all degrees of heart block, idioventricular rhythm, etc), all without an arterial pressure. Attempts to correct these rhythms with pharmacologic therapy or with pacemakers are of no avail. Therapy must be directed toward the restoration of myocardial perfusion. In contrast, the patient with heart block or other severe bradydysrhythmias in which there is a palpable pulse generated with the QRS complex usually respond well to pharmacologic intervention or pacing. The prognosis of patients with EMD is poor, but rational therapy implies the application of techniques that increase coronary perfusion and thereby decrease the diffuse myocardial ischemia.
Topics: Animals; Arrhythmias, Cardiac; Dogs; Electrocardiography; Humans; Resuscitation
PubMed: 6476549
DOI: 10.1016/s0196-0644(84)80452-7