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Journal of Cardiovascular Pharmacology... Oct 1997BACKGROUND: Propafenone has been claimed to be effective in converting atrial fibrillation and flutter to sinus rhythm; however, controlled clinical trials have reported...
BACKGROUND: Propafenone has been claimed to be effective in converting atrial fibrillation and flutter to sinus rhythm; however, controlled clinical trials have reported variable results, and data about the safety of propafenone in the setting of heart failure are lacking. The aim of the present study was to evaluate the efficacy and safety of intravenous propafenone in converting atrial fibrillation and flutter to sinus rhythm. METHODS: Sixty patients with acute (<72 h) or chronic atrial fibrillation or flutter were included in a randomized, placebo-controlled, conditional cross-over study. Twenty eight patients, of whom 12 were in New York Heart Association class III and IV, had heart failure. Patients received intravenous propafenone (2 mg/kg in 10 minutes) and placebo subsequently at 1 hour intervals if sinus rhythm was not achieved. The patients' rhythms were continuously monitored for 1 hour and a 12-lead electrocardiogram, a 1-minute continuous rhythm strip and vital signs were recorded at baseline and at 15, 30, 45, and 60 minutes after the administration of each drug. RESULTS: Twenty of teh 59 patients (34%) treated with propafenone converted to sinus rhythm, while only 4 of the 50 patients (8%) treated with placebo converted (P <.001). Propafenone was more effective in patients with acute (<72 h) atrial fibrillation (64.5%). The conversion rate with propafenone was not significantly different from placebo in patients with atrial flutter and chronic atrial fibrillation (>72 h). Propafenone significantly decreased (P <.005 vs placebo) mean ventricular rate in nonresponders with a baseline heart rate of more than 100 beats/min. No clinically significant adverse effect occurred. CONCLUSIONS: We conclude that intravenous propafenone treatment is effective for converting acute atrial fibrillation; however, it seems unlikely to be beneficial in atrial flutter and chronic atrial fibrillation. Propafenone decreases ventricular rate in nonresponders, and a single dose of propafenone is relatively safe even in moderate-to-severe heart failure.
PubMed: 10684466
DOI: 10.1177/107424849700200403 -
Prehospital Emergency Care 2023Adenosine has been safely used by paramedics for the treatment of stable supraventricular tachycardia since the mid-1990s. However, there continues to be variability in...
BACKGROUND
Adenosine has been safely used by paramedics for the treatment of stable supraventricular tachycardia since the mid-1990s. However, there continues to be variability in paramedics' ability to identify appropriate indications for adenosine administration. As the first of a planned series of studies aimed at improving the accuracy of SVT diagnosis and successful administration of adenosine by paramedics, this study details the current usage patterns of adenosine by paramedics.
METHODS
This cross-sectional retrospective study investigated adenosine use within a large northeast EMS region from January 1, 2019, through September 30, 2021. Excluding pediatric and duplicate case reports, we created a dataset containing patient age, sex, and vital signs before, during, and after adenosine administration; intravenous line location; and coded medical history from paramedic narrative documentation, including a history of atrial fibrillation, suspected arrhythmia diagnosis, and effect of adenosine. In cases with available prehospital electrocardiograms (EKGs) for review, two physicians independently coded the arrhythmia diagnosis and outcome of adenosine administration. Statistical analysis included interrater reliability with Cohen's kappa statistic.
RESULTS
One hundred eighty-three cases were included for final analysis, 84 did not have a documented EKG for review. Categorization of presenting rhythms in these cases occurred by a physician reviewing EMS narrative and documentation. Forty of these 84 cases (48%) were adjudicated as SVT likely, 32 (38%) as SVT unlikely and 12 (14%) as uncategorized due to lack of supporting documentation. Of the 99 cases with EKGs available to review, there was substantial agreement of arrhythmia diagnosis interpretation between physician reviewers (Cohen's kappa 0.77-1.0); 54 cases were adjudicated as SVT by two physician reviewers. Other identified cardiac rhythms included atrial fibrillation (16), sinus tachycardia (11), and ventricular tachycardia (2). Adenosine cardioversion occurred in 47 of the 99 cases with EKGs available for physician review (47.5%). Adenosine cardioversion was also deemed to occur in 87% (47/54) of cases when the EKG rhythm was physician adjudicated SVT.
CONCLUSIONS
This study supports the use of adenosine as a prehospital treatment for SVT while highlighting the need for continued efforts to improve paramedics' identification and management of tachyarrhythmias.
Topics: Humans; Child; Adenosine; Atrial Fibrillation; Retrospective Studies; Cross-Sectional Studies; Reproducibility of Results; Emergency Medical Services; Prospective Studies; Tachycardia, Supraventricular
PubMed: 35639665
DOI: 10.1080/10903127.2022.2084579 -
Journal of Electrocardiology 2015Identification of atrial fibrillation (AF) is a clinical imperative. Heartbeat interval time series are increasingly available from personal monitors, allowing new...
BACKGROUND
Identification of atrial fibrillation (AF) is a clinical imperative. Heartbeat interval time series are increasingly available from personal monitors, allowing new opportunity for AF diagnosis.
GOAL
Previously, we devised numerical algorithms for identification of normal sinus rhythm (NSR), AF, and SR with frequent ectopy using dynamical measures of heart rate. Here, we wished to validate them in the canonical MIT-BIH ECG databases.
METHODS
We tested algorithms on the NSR, AF and arrhythmia databases.
RESULTS
When the databases were combined, the positive predictive value of the new algorithms exceeded 95% for NSR and AF, and was 40% for SR with ectopy. Further, dynamical measures did not distinguish atrial from ventricular ectopy. Inspection of individual 24hour records showed good correlation of observed and predicted rhythms.
CONCLUSION
Heart rate dynamical measures are effective ingredients in numerical algorithms to classify cardiac rhythm from the heartbeat intervals time series alone.
Topics: Algorithms; Atrial Fibrillation; Databases, Factual; Diagnosis, Computer-Assisted; Electrocardiography; Heart Rate; Humans; Reproducibility of Results; Sensitivity and Specificity
PubMed: 26320371
DOI: 10.1016/j.jelectrocard.2015.08.002 -
Journal of Arrhythmia Jun 2024The concept of ablation index (AI) was introduced to evaluate radiofrequency (RF) ablation lesions. It is calculated from power, contact force (CF), and RF duration....
BACKGROUND
The concept of ablation index (AI) was introduced to evaluate radiofrequency (RF) ablation lesions. It is calculated from power, contact force (CF), and RF duration. However, other factors may also affect the quality of ablation lesions. To examine the difference in RF lesions made during sinus rhythm (SR) and atrial fibrillation (AF).
METHODS
Sixty patients underwent index pulmonary vein isolation during SR ( = 30, SR group) or AF ( = 30, AF group). All ablations were performed with a power of 50 W, a targeted CF of 5-15 g, and AI of 400-450 using Thermocool Smarttouch SF. The CF, AI, RF duration, temperature rise (Δtemp), impedance drop (Δimp), and the CF stability of each ablation point quantified as the standard deviation of the CF (CF-SD) were compared between the two groups.
RESULTS
A total of 3579 ablation points were analyzed, which included 1618 and 1961 points in the SR and the AF groups, respectively. Power, average CF, RF duration per point, and the resultant AI (389 ± 59 vs. 388 ± 57) were similar for the two rhythms. However, differences were seen in the CF-SD (3.5 ± 2.2 vs. 3.8 ± 2.1 g, < .01), Δtemp (3.8 ± 1.3 vs. 4.0 ± 1.3°C, < .005), and Δimp (10.3 ± 5.8 vs. 9.4 ± 5.4 Ω, < .005).
CONCLUSIONS
Despite similar AI, various RF parameters differed according to the underlying atrial rhythm. Ablation delivered during SR demonstrated less CF variability and temperature increase and greater impedance drop than during AF.
PubMed: 38939764
DOI: 10.1002/joa3.13025 -
Disease-a-month : DM Feb 2024Sudden alterations in the heart rate may be associated with diverse symptoms. Sinus node dysfunction (SND), also known as sick sinus syndrome, is a sinoatrial (SA) node... (Review)
Review
Sudden alterations in the heart rate may be associated with diverse symptoms. Sinus node dysfunction (SND), also known as sick sinus syndrome, is a sinoatrial (SA) node disorder. SND is primarily caused by the dysfunction of the pacemaker, as well as impaired impulse transmission resulting in a multitude of abnormalities in the heart rhythms, such as bradycardia-tachycardia, atrial bradyarrhythmias, and atrial tachyarrhythmias. The transition from bradycardia to tachycardia is generally referred to as "tachy-brady syndrome" (TBS). Although TBS is etiologically variable, the manifestations remain consistent throughout. Abnormal heart rhythms have the propensity to limit tissue perfusion resulting in palpitations, fatigue, lightheadedness, presyncope, and syncope. In this review, we examine the physiology of tachy-brady syndrome, the practical approach to its diagnosis and management, and the role of adenosine in treating SND.
Topics: Humans; Sick Sinus Syndrome; Bradycardia; Sinoatrial Node; Tachycardia; Electrophysiology
PubMed: 37690863
DOI: 10.1016/j.disamonth.2023.101637 -
Cardiology 1991We have investigated resting electrocardiograms from 1,299 athletic students taken in the same laboratory during the years 1973-1982 and compared them with... (Review)
Review
We have investigated resting electrocardiograms from 1,299 athletic students taken in the same laboratory during the years 1973-1982 and compared them with electrocardiograms recorded in 151 age- and sex-matched sedentary controls. Fifty-two parameters were recorded for each electrocardiogram and computerized. We found that athletic students had a significant lower heart rate, longer PQ time and a prolonged QTc compared to control subjects. Athletes had higher maximal Q amplitudes in precordial leads, higher R in V1, and higher indices of right ventricular hypertrophy (RV1 + SV5) and left ventricular hypertrophy (Sokolow-Lyon and Grant indices). Furthermore, the athletes had higher maximal ST elevation and higher maximal T wave amplitudes in precordial leads. Sinus bradycardia was more frequent in athletes. All control subjects were in sinus rhythm whereas 0.9% of the athletes had other rhythms (nodal, coronary sinus or wandering pacemaker). Athletes and control subjects did not differ significantly with regard to premature beats, atrioventricular block, bundle branch block or the Wolff-Parkinson-White pattern. We conclude that training induces significant changes in heart rate, conduction times, ST elevation. QRS and T voltage, slow rhythm disturbances and atrioventricular and sinoatrial block were infrequent in the resting electrocardiogram taken in the supine position and disappeared immediately on sitting and during exercise. Training-induced electrocardiographic changes may partly be due to alterations in autonomic tone and partly to structural changes in the myocardium. Different normal criteria for left ventricular hypertrophy may be warranted in athletes.
Topics: Adolescent; Adult; Animals; Arrhythmias, Cardiac; Dogs; Electrocardiography; Evaluation Studies as Topic; Female; Heart Conduction System; Heart Rate; Humans; Male; Middle Aged; Sports; Time Factors
PubMed: 1782647
DOI: 10.1159/000174893 -
Current Medical Science Dec 2020Lorenz-RR scatter plot has an obvious shortcoming in that it does not indicate the time when the scatter point happens. On the Lorenz RR scatter plot, one cannot know...
Lorenz-RR scatter plot has an obvious shortcoming in that it does not indicate the time when the scatter point happens. On the Lorenz RR scatter plot, one cannot know the time during which the cardiac rhythms take place. Since occurrence of cardiac rhythms is time-related, time should be introduced to such plots. In this study, time was used as abscissa and RR interval (the time interval between the previous RR wave and the R wave) as the ordinate and time was compressed into a visually observable length, and thereby a timed RR-interval scatter plot, or t-RR scatter plot, for short, was developed. On t-RR scatter plot, the patterns were band-shaped or were of linear type. On the t-RR plot, the sinus rhythm presented bands of various widths, with the spiculate or burred upper and lower boundaries, having diurnal variation. Premature beats showed separate layers ("stratification"), the layer number corresponding the number of RR-intervals. With simple premature beats, the layers were clearly separated. With parasystole rhythm, the upper and lower bands or layers might become thicker. With arial premature beats, the space or distance between layers varied. Ventricular premature beats presented equal space or distance between layers. With tachycardia, the lower layer became a "solid" layer. With atrial fibration, the "stratification" disappeared, presenting thicker or widened layers or bands, with neat lower boundary. With atrial flutter, the layers went parallel, with the layers being evenly separated or some distances being exact multiples of others. The second degree atrioventricular block displayed two layers, the lower and upper bands being equally away from the X-axis, presenting a straight line (pacing at a fixed rate) or a thicker or wider bands, with a neat upper boundary (the lowest pacing rate). When the scatter plot presented uncharacteristic patterns or had some scattered points, which rendered diagnosis difficult, a reverse technology could be used. Briefly, upon selection of scattered points, they were subjected to computerization, by regression, to reveal the piece of electrocardiogram (ECG) containing an R wave (QRS complex). Then ECG was analyzed to diagnose the cardiac rhythms. In conclusion, t-RR is a novel methodology which helps us understand heart rhythms from a new perspective.
Topics: Arrhythmias, Cardiac; Electrocardiography; Heart; Heart Rate; Humans; Signal Processing, Computer-Assisted; Time Factors
PubMed: 33428149
DOI: 10.1007/s11596-020-2308-8 -
The American Journal of Cardiology Jan 1988Animal data suggest that cardiac arrhythmias can result from a variety of mechanisms. In clinical settings, arrhythmias that are easily initiated and terminated with... (Review)
Review
Animal data suggest that cardiac arrhythmias can result from a variety of mechanisms. In clinical settings, arrhythmias that are easily initiated and terminated with programmed electrical stimulation are often designated as reentry tachycardias. However, proof of reentry is contingent upon demonstration of the entire circuit; this relation has been proposed for arrhythmias associated with large circuits, such as those seen in the Wolff-Parkinson-White syndrome. Reentry has also been proposed as the mechanism responsible for a variety of other tachycardias, including bundle branch and atrioventricular nodal reentry tachycardia, permanent junctional reentrant tachycardia, reentry tachycardia associated with nodoventricular Mahaim fibers and inducible atrial and ventricular tachycardia. Documentation of triggered rhythms as the mechanism responsible for clinical arrhythmias has been even more difficult. Examples of arrhythmias resulting from triggered activity may include those associated with digitalis toxicity arising from the atria, the atrioventricular junction or the ventricles. Clinical arrhythmias due to triggered activity in the absence of digitalis have also been described. Cardiac arrhythmias that cannot be induced by electrical stimulation are presumably due to normal or abnormal automaticity. Examples of normal automaticity in the human heart are sinus rhythm and junctional and idioventricular escape rhythms. Tachycardias by abnormal automaticity have seldom been investigated for the purpose of documenting the mechanism and therefore the limited data available make it difficult to draw any final conclusions.
Topics: Animals; Cardiac Pacing, Artificial; Cattle; Dogs; Electric Stimulation; Electrocardiography; Heart; Heart Conduction System; Humans; Membrane Potentials; Rabbits; Tachycardia; Tachycardia, Atrioventricular Nodal Reentry; Wolff-Parkinson-White Syndrome
PubMed: 3276129
DOI: 10.1016/0002-9149(88)90736-9 -
Journal of Electrocardiology Jul 2005We examined the accuracy of computer-based rhythm interpretation from one electrocardiograph manufacturer (GE Healthcare Technologies MUSE software 005C) in 4297... (Comparative Study)
Comparative Study
We examined the accuracy of computer-based rhythm interpretation from one electrocardiograph manufacturer (GE Healthcare Technologies MUSE software 005C) in 4297 consecutive recordings in a university hospital setting. Overreading was performed by either of 2 experienced cardiologists, and all disagreements with the initial computer rhythm statement were reviewed by the second cardiologist to achieve physician consensus used as the "gold standard" for rhythm diagnosis. Overall, 13.2% (565/4297) of computer-based rhythm statements required revision, but excluding tracings with pacemakers, the revision rate was 7.8% (307/3954), including 3.8% involving the primary rhythm diagnosis and 3.9% involving definition of ectopic complexes. The false-negative rate for sinus rhythm was only 1.3%, but a computer diagnosis of sinus rhythm was incorrect in 9.9% of other rhythms. The false-negative rate for atrial fibrillation was 9.2%, whereas a computer diagnosis of atrial fibrillation was incorrect in 1.1% of other rhythms, including sinus. Computer diagnosis of paced rhythms remains problematic, and physician overreading to correct computer-based electrocardiogram rhythm diagnoses remains mandatory.
Topics: Algorithms; Atrial Fibrillation; Atrial Flutter; Atrial Premature Complexes; Cardiac Complexes, Premature; Cardiac Pacing, Artificial; Diagnosis, Computer-Assisted; Electrocardiography; False Negative Reactions; Heart Block; Heart Rate; Humans; Observer Variation; Pacemaker, Artificial; Sensitivity and Specificity; Tachycardia, Ectopic Atrial; Ventricular Premature Complexes
PubMed: 16003708
DOI: 10.1016/j.jelectrocard.2005.01.008 -
Circulation. Arrhythmia and... Oct 2015During left atrial mapping, optimal contact parameters minimizing variation secondary to catheter contact are not established.
BACKGROUND
During left atrial mapping, optimal contact parameters minimizing variation secondary to catheter contact are not established.
METHODS AND RESULTS
Across 30 patients undergoing first-time atrial fibrillation ablation, 1965 stable mapping points (1409 atrial fibrillation, 556 sinus rhythm), comprising 8-s contact force (CF) and bipolar electrogram data were analyzed. Points were taken in groups at locations with CF or catheter orientation actively changed between acquisitions. Complexes were less positive at higher CF (Spearman ρ, -0.2; P<0.005, both rhythms). Increasing CF at a location significantly increased complex size, but only where initial CF was <10 g, and if the change was ≥4.5 g in sinus rhythm and ≥8 g in atrial fibrillation (P<0.0005, both rhythms): if initial CF was ≥10 g, no change was observed, regardless of CF change (P>0.05, both). Atrial ectopics during sinus rhythm were observed more frequently when CF was ≥10 g (P<0.0005). Increasing CF at a location was associated with an increase in the complex fractionated atrial electrogram interval confidence level score, but only if initial CF was <10 g and CF increased ≥8 g (P=0.003). The dominant frequency and organization index were unaffected by CF (P>0.1 for both). Changing catheter orientation from perpendicular to parallel in atrial fibrillation was associated with smaller, more positive complexes (P=0.001 for both), but no changes in complex fractionated atrial electrogram scores, dominant frequency or organization index (P>0.08 for each).
CONCLUSIONS
During left atrial electrogram mapping, including complex fractionated atrial electrogram but not spectral parameter mapping, CF and catheter orientation influence results: consequently, mapping CFs should be ≥10 g to negate the influence of CF.
CLINICAL TRIALS REGISTRATION
URL: http://clinicaltrials.gov/. Unique identifier: NCT01587404.
Topics: Atrial Fibrillation; Cardiac Catheters; Catheter Ablation; Electrophysiologic Techniques, Cardiac; Female; Humans; Male; Middle Aged; Stress, Mechanical; Treatment Outcome
PubMed: 26152560
DOI: 10.1161/CIRCEP.114.002483