ABSTRACT
A 32-year-old woman underwent radiofrequency catheter ablation of narrow QRS tachycardia that was terminated with intravenous adenosine.
Subject(s)
Atrial Premature Complexes/diagnosis , Bundle of His/physiopathology , Cardiac Pacing, Artificial , Electrophysiologic Techniques, Cardiac , Tachycardia, Ventricular/diagnosis , Action Potentials , Adult , Atrial Premature Complexes/physiopathology , Atrial Premature Complexes/surgery , Catheter Ablation , Electrocardiography , Female , Heart Rate , Humans , Predictive Value of Tests , Tachycardia, Ventricular/physiopathology , Tachycardia, Ventricular/surgery , Time Factors , Treatment OutcomeSubject(s)
Atrial Premature Complexes/diagnosis , Bundle-Branch Block/diagnosis , Electrophysiologic Techniques, Cardiac , Heart Conduction System/physiopathology , Heart Rate , Tachycardia, Ventricular/diagnosis , Ablation Techniques , Action Potentials , Atrial Premature Complexes/physiopathology , Bundle-Branch Block/physiopathology , Electrocardiography , Female , Heart Conduction System/surgery , Humans , Middle Aged , Predictive Value of Tests , Tachycardia, Ventricular/physiopathology , Tachycardia, Ventricular/surgery , Time FactorsABSTRACT
A 14-year-old girl with a history of recurrent palpitations and documented wide QRS complex tachycardia was referred for electrophysiologic study and catheter ablation.
Subject(s)
Accessory Atrioventricular Bundle , Atrial Premature Complexes/diagnosis , Tachycardia, Ventricular/diagnosis , Action Potentials , Adolescent , Atrial Premature Complexes/physiopathology , Atrial Premature Complexes/surgery , Catheter Ablation , Diagnosis, Differential , Electrocardiography , Electrophysiologic Techniques, Cardiac , Female , Heart Rate , Humans , Predictive Value of Tests , Tachycardia, Ventricular/physiopathology , Tachycardia, Ventricular/surgery , Treatment OutcomeSubject(s)
Action Potentials , Atrial Premature Complexes/diagnosis , Cardiac Pacing, Artificial , Electrophysiologic Techniques, Cardiac , Heart Rate , Tachycardia, Atrioventricular Nodal Reentry/diagnosis , Atrial Premature Complexes/physiopathology , Atrial Premature Complexes/surgery , Catheter Ablation/adverse effects , Female , Humans , Middle Aged , Predictive Value of Tests , Recurrence , Reoperation , Tachycardia, Atrioventricular Nodal Reentry/physiopathology , Tachycardia, Atrioventricular Nodal Reentry/surgery , Time Factors , Treatment OutcomeABSTRACT
Low magnesium may increase the risk of atrial fibrillation. We conducted a double-blind pilot randomized trial to assess adherence to oral magnesium supplementation (400 mg of magnesium oxide daily) and a matching placebo, estimate the effect on circulating magnesium concentrations, and evaluate the feasibility of using an ambulatory heart rhythm monitoring device (ZioPatch) for assessing premature atrial contractions. A total of 59 participants were randomized; 73% were women, and the mean age was 62 years. A total of 98% of the participants completed the follow-up. In the magnesium supplement group, 75% of pills were taken, and in the placebo group, 83% were taken. The change in magnesium concentrations was significantly greater for those given the magnesium supplements than for those given the placebo (0.07; 95% confidence interval: 0.03, 0.12 mEq/L; p = 0.002). The ZioPatch wear time was approximately 13 of the requested 14 days at baseline and follow-up. There was no difference by intervention assignment in the change in log premature atrial contractions burden, glucose, or blood pressure. Gastrointestinal changes were more common among the participants assigned magnesium (50%) than among those assigned the placebo (7%), but only one person discontinued participation. In sum, compliance with the oral magnesium supplementation was very good, and acceptance of the ZioPatch monitoring was excellent. These findings support the feasibility of a larger trial for atrial fibrillation (AF) prevention with oral magnesium supplementation.
Subject(s)
Anti-Arrhythmia Agents/administration & dosage , Atrial Fibrillation/drug therapy , Atrial Premature Complexes/drug therapy , Dietary Supplements , Heart Rate/drug effects , Magnesium Oxide/administration & dosage , Administration, Oral , Aged , Anti-Arrhythmia Agents/adverse effects , Atrial Fibrillation/diagnosis , Atrial Fibrillation/physiopathology , Atrial Premature Complexes/diagnosis , Atrial Premature Complexes/physiopathology , Dietary Supplements/adverse effects , Double-Blind Method , Electrocardiography, Ambulatory/instrumentation , Feasibility Studies , Female , Humans , Magnesium Oxide/adverse effects , Male , Medication Adherence , Middle Aged , Minnesota , Pilot Projects , Predictive Value of Tests , Signal Processing, Computer-Assisted , Time Factors , Transducers , Treatment OutcomeSubject(s)
Action Potentials , Atrial Premature Complexes/physiopathology , Bundle-Branch Block/physiopathology , Heart Conduction System/physiopathology , Heart Rate , Tachycardia, Ventricular/physiopathology , Aged , Atrial Premature Complexes/diagnosis , Bundle-Branch Block/diagnosis , Cardiac Pacing, Artificial , Electrocardiography , Electrophysiologic Techniques, Cardiac , Humans , Male , Tachycardia, Ventricular/diagnosis , Time FactorsSubject(s)
Atrial Fibrillation/surgery , Atrial Premature Complexes/surgery , Catheter Ablation , Pulmonary Veins/surgery , Tachycardia, Supraventricular/surgery , Action Potentials , Atrial Fibrillation/diagnosis , Atrial Fibrillation/physiopathology , Atrial Premature Complexes/diagnosis , Atrial Premature Complexes/physiopathology , Electrocardiography , Electrophysiologic Techniques, Cardiac , Heart Rate , Humans , Male , Middle Aged , Predictive Value of Tests , Pulmonary Veins/physiopathology , Tachycardia, Supraventricular/diagnosis , Tachycardia, Supraventricular/physiopathology , Treatment OutcomeABSTRACT
Aims: To confirm the presence of tachycardia-induced slur or notch in the terminal portion of the QRS complexes in a general patient population. Methods and results: A tachycardia-induced J wave was defined as a slur or notch in the terminal portion of the QRS complexes newly induced at short RR intervals during atrial premature contractions (APCs) or atrial electrical stimulation in the electrophysiological study (EPS). Twenty-three out of 2000 patients with general diseases were involved. All patients with aborted sudden cardiac death, ventricular fibrillation or a family history of sudden cardiac death were excluded. The mean age was 72 ± 9 years, and 11 patients were male (47.8%). When the RR interval was shortened from 821 ± 142 ms to 464 ± 52 ms in the conducted APCs (P < 0.0001), J waves became diagnostic (0.02 ± 0.03 mV to 0.20 ± 0.07 mV, P < 0.0001). J waves were confined to the inferior leads in 22 (95.7%) patients and were notched in 11 (47.8%) and slurred in 12 (52.2%) patients. The induction of J waves was accompanied by visible changes of the QRS morphology. When the post-APC RR interval was prolonged to 992 ± 305 ms (P = 0.0154 vs. baseline), the J waves were similar to baseline levels. During the EPS, J wave induction was confirmed during atrial stimulation. There were no characteristic clinical or ECG features in the patients with tachycardia-induced J waves. Conclusions: J waves can be newly induced by short RR intervals in a general patient population, and a conduction delay is the likely mechanism causing such J waves.
Subject(s)
Action Potentials , Atrial Premature Complexes/physiopathology , Heart Atria/physiopathology , Heart Rate , Tachycardia, Supraventricular/physiopathology , Aged , Atrial Premature Complexes/diagnosis , Cardiac Pacing, Artificial , Electrocardiography , Electrophysiologic Techniques, Cardiac , Female , Humans , Male , Middle Aged , Tachycardia, Supraventricular/diagnosis , Time FactorsSubject(s)
Atrial Premature Complexes/physiopathology , Heart Conduction System/physiopathology , Tachycardia, Atrioventricular Nodal Reentry/physiopathology , Action Potentials , Adult , Atrial Premature Complexes/diagnosis , Atrial Premature Complexes/surgery , Catheter Ablation , Electrocardiography , Electrophysiologic Techniques, Cardiac , Female , Heart Conduction System/surgery , Heart Rate , Humans , Tachycardia, Atrioventricular Nodal Reentry/diagnosis , Tachycardia, Atrioventricular Nodal Reentry/surgeryABSTRACT
AIMS: Frequent premature atrial contractions (PACs) are associated with increased risk of atrial fibrillation (AF), stroke, and death. This study aimed to explore the electrophysiological features of PACs with and without inducing AF and to evaluate the effectiveness of catheter ablation for PACs. METHODS AND RESULTS: Thirty-five consecutive patients with symptomatic, frequent, and drug-refractory PACs in the absence of AF (group A) and 35 patients with PACs-induced AF (group B) were enrolled. Coupling intervals (CoIs) of PACs were compared. Premature atrial contractions were mapped by the point-by-point and/or circular mapping technique. Focal ablation or pulmonary vein/superior vena cava isolation was applied as appropriate. A total of 35 ectopic foci were identified in group A. The majority of them were at pulmonary vein (PV) (n = 7), crista terminalis (n = 6), and para-Hisian area (n = 6). In group B, ectopic foci were in left-sided PVs in 21 patients, in right-sided PVs in 13 patients, and in SVC in 1 patient. There was significant difference in CoIs of PACs triggering AF and those from PVs and non-PV areas but without causing AF (362.8 ± 23.0 ms vs. 470.6 ± 60.1 ms vs. 515.6 ± 77.2 ms, P< 0.001). Premature atrial contractions were abolished in 32 of 35 patients from group A and in all patients from group B. At the end of follow-up, 29 patients in group A and 28 patients in group B were free of recurrence (off antiarrhythmic drugs) after the initial ablation (P =0.97). CONCLUSIONS: Frequent PACs in the absence of AF were characterized as having their predilection sites and longer CoIs than those inducing AF. Catheter ablation was effective to eliminate symptomatic, frequent, and drug-refractory PACs.
Subject(s)
Atrial Premature Complexes/surgery , Catheter Ablation , Electrocardiography, Ambulatory , Electrophysiologic Techniques, Cardiac , Pulmonary Veins/surgery , Action Potentials , Aged , Anti-Arrhythmia Agents/therapeutic use , Atrial Premature Complexes/diagnosis , Atrial Premature Complexes/physiopathology , Case-Control Studies , Catheter Ablation/adverse effects , Disease-Free Survival , Female , Heart Rate , Humans , Male , Middle Aged , Predictive Value of Tests , Pulmonary Veins/physiopathology , Recurrence , Time Factors , Treatment OutcomeABSTRACT
BACKGROUND: Premature cardiac contractions are associated with increased morbidity and mortality. Though experts associate premature atrial contractions (PACs) and premature ventricular contractions (PVCs) with caffeine, there are no data to support this relationship in the general population. As certain caffeinated products may have cardiovascular benefits, recommendations against them may be detrimental. METHODS AND RESULTS: We studied Cardiovascular Health Study participants with a baseline food frequency assessment, 24-hour ambulatory electrocardiography (Holter) monitoring, and without persistent atrial fibrillation. Frequencies of habitual coffee, tea, and chocolate consumption were assessed using a picture-sort food frequency survey. The main outcomes were PACs/h and PVCs/hour. Among 1388 participants (46% male, mean age 72 years), 840 (61%) consumed ≥1 caffeinated product per day. The median numbers of PACs and PVCs/h and interquartile ranges were 3 (1-12) and 1 (0-7), respectively. There were no differences in the number of PACs or PVCs/h across levels of coffee, tea, and chocolate consumption. After adjustment for potential confounders, more frequent consumption of these products was not associated with ectopy. In examining combined dietary intake of coffee, tea, and chocolate as a continuous measure, no relationships were observed after multivariable adjustment: 0.48% fewer PACs/h (95% CI -4.60 to 3.64) and 2.87% fewer PVCs/h (95% CI -8.18 to 2.43) per 1-serving/week increase in consumption. CONCLUSIONS: In the largest study to evaluate dietary patterns and quantify cardiac ectopy using 24-hour Holter monitoring, we found no relationship between chronic consumption of caffeinated products and ectopy.
Subject(s)
Atrial Premature Complexes/chemically induced , Cacao/adverse effects , Caffeine/adverse effects , Coffee/adverse effects , Diet/adverse effects , Heart Rate/drug effects , Tea/adverse effects , Ventricular Premature Complexes/chemically induced , Aged , Atrial Premature Complexes/diagnosis , Atrial Premature Complexes/physiopathology , Caffeine/administration & dosage , Electrocardiography, Ambulatory , Feeding Behavior , Female , Humans , Male , Prospective Studies , Recommended Dietary Allowances , Risk Assessment , Risk Factors , Surveys and Questionnaires , Time Factors , United States , Ventricular Premature Complexes/diagnosis , Ventricular Premature Complexes/physiopathologyABSTRACT
BACKGROUND: A left-to-right dominant frequency (DF) gradient commonly exists in paroxysmal atrial fibrillation (AF). AF initiated by right atrial (RA) ectopy (AF-RAE) is rare. OBJECTIVE: This study aimed to investigate characteristics of AF-RAE using pharmacological maneuvers and spectral analysis. METHODS: Seventy-nine consecutive patients referred for catheter ablation of paroxysmal AF were enrolled. Infusions of isoproterenol and adenosine triphosphate (ATP) were used to induce AF. Patients with AF-RAE and patients with AF initiated only by pulmonary vein (PV) ectopies were classified into the RA-ectopy group (n = 7[9%]) and PV-ectopy group (n = 32[41%]), respectively. ATP was also injected during ongoing AF to unmask the driver of AF. High RA, coronary sinus, and PV-left atrial junction electrograms and electrocardiogram lead V1 underwent spectral analyses. RESULTS: Patients in the RA-ectopy group were younger (51 ± 13 years vs 63 ± 7 years; P = .01) and more commonly had a family history of AF (71% vs 9%; P < .001) than patients in the PV-ectopy group. There was a baseline right-to-left DF gradient in the RA-ectopy group (PV-left atrial junction: 6.0 ± 0.4 Hz; coronary sinus: 5.7 ± 0.6 Hz; RA: 7.3 ± 0.8 Hz; P < .05) in contrast to a left-to-right DF gradient in the PV-ectopy group (5.9 ± 0.8, 5.3 ± 0.7, 5.2 ± 0.8 Hz; P < .01). ATP injection predominantly increased the DF of the high RA in the RA-ectopy group and augmented a right-to-left DF gradient (7.9 ± 1.8, 7.6 ± 1.0, 10.7 ± 0.7 Hz; P < .001), whereas it augmented a left-to-right DF gradient in the PV-ectopy group (7.9 ± 1.0, 6.4 ± 0.5, 6.6 ± 1.2 Hz; P < .05). CONCLUSION: A rare type of paroxysmal AF initiated by RA ectopy may be maintained by a reentrant driver localized in the RA (so-called RA fibrillation).
Subject(s)
Adenosine Triphosphate/pharmacology , Atrial Fibrillation , Atrial Premature Complexes , Catheter Ablation/methods , Isoproterenol/pharmacology , Adult , Aged , Atrial Fibrillation/diagnosis , Atrial Fibrillation/physiopathology , Atrial Fibrillation/surgery , Atrial Premature Complexes/diagnosis , Atrial Premature Complexes/physiopathology , Cardiovascular Agents/pharmacology , Electrophysiologic Techniques, Cardiac/methods , Humans , Middle Aged , Preoperative CareABSTRACT
Episodes of atrial fibrillation (AF) are mainly initiated by triggers from pulmonary veins (PVs). The superior vena cava (SVC) has been identified as a second major substrate of non-PV foci, but the electrophysiologic features of the SVC have not been fully investigated. We hypothesized that SVC ectopies are suppressed by predominant features of PV ectopies and tend to appear after PV isolation (PVI). We evaluated the electrophysiological characteristics and clinical implications of SVC ectopies in patients with AF during catheter ablation using high-dose isoproterenol and the atrial overdrive pacing maneuver. The manifestation patterns and modes of onset (coupling interval and appearance interval) of ectopies from both the PVs and SVC were investigated. 205 patients were enrolled [153 males and 52 females; mean age 64 ± 10 years; paroxysmal in 143 patients (69.8 %), persistent in 40 (19.5 %), and long-standing persistent in 22 patients (10.7 %)]. Before PVI, PV ectopies were detected in 182/205 patients (89 %). SVC ectopies were rarely observed before PVI but were significantly more frequent after the completion of PVI (3/205 vs. 14/205 patients, p = 0.011). The coupling interval (CI) and % CI (CI/preceding the A-A interval × 100) of PV ectopies were significantly shorter than those of SVC ectopies (211 ± 78 vs. 282 ± 106 ms, p = 0.021, and 34 ± 9 vs. 51 ± 17 %, p < 0.001, respectively). The appearance intervals of the PV ectopies were shorter than those of the SVC ectopies (6.3 ± 4.0 vs. 10.7 ± 6.7 s, p = 0.030). During repeat procedures, PVs with reconnection to the left atrium were less frequently observed in patients with SVC firing than in patients without SVC firing (1.7 ± 1.5 vs. 2.9 ± 1.1 PVs, p = 0.029). We demonstrated that PVI tends to manifest SVC ectopies with less spontaneous activity and that an elimination of predominant ectopies from the PVs may affect appearance of SVC ectopy.
Subject(s)
Atrial Fibrillation/surgery , Atrial Premature Complexes/surgery , Catheter Ablation/adverse effects , Heart Rate , Pulmonary Veins/surgery , Vena Cava, Superior/physiopathology , Action Potentials , Adrenergic beta-Agonists/administration & dosage , Aged , Atrial Fibrillation/diagnosis , Atrial Fibrillation/physiopathology , Atrial Premature Complexes/diagnosis , Atrial Premature Complexes/physiopathology , Cardiac Pacing, Artificial , Electrophysiologic Techniques, Cardiac , Female , Humans , Isoproterenol/administration & dosage , Male , Middle Aged , Predictive Value of Tests , Pulmonary Veins/physiopathology , Recurrence , Reoperation , Retrospective Studies , Time Factors , Treatment Outcome , Vena Cava, Superior/surgeryABSTRACT
BACKGROUND: The relevance of focal triggers in persistent atrial fibrillation (PerAF) and long-standing persistent atrial fibrillation (LSPAF) has not been previously investigated. OBJECTIVE: We prospectively evaluated the prevalence and distribution of AF triggers in patients referred for catheter ablation of PerAF and LSPAF. METHODS: We analyzed consecutive patients undergoing first time AF ablation who underwent a standardized trigger protocol including cardioversion of induced or spontaneous AF and infusion of up to 20 µg of isoproterenol for 15-20 minutes either before or after pulmonary vein (PV) isolation accomplished. Triggers were defined as AF/sustained atrial tachyarrhythmia or repetitive atrial premature depolarizations. RESULTS: A total of 2168 patients were included (mean age 57 ± 11 years; 1636 [75%] men), with 1531 patients having paroxysmal AF (PAF) (71%), 496 having PerAF (23%), and 141 having LSPAF (7%). PV triggers were found in 1398 patients with PAF (91%), 449 patients with PerAF (91%), and 129 patients with LSPAF (91%) (P = .856 for comparison across groups). Non-PV triggers were elicited in a total of 234 patients (11%), and the prevalence was similar across the different types of AF (PAF, 165 [11%]; PerAF, 54 [11%]; LSPAF, 15 [11%]; P = .996 for comparison across groups). CONCLUSION: PVs are the main AF trigger site in patients with PerAF and LSPAF, with an overall prevalence similar to that found in patients with PAF. These results support the current recommendations for PV isolation as the cornerstone of catheter ablation to eliminate AF triggers in PerAF and LSPAF.
Subject(s)
Atrial Fibrillation , Atrial Premature Complexes/physiopathology , Catheter Ablation/methods , Tachycardia, Ectopic Atrial/physiopathology , Aged , Atrial Fibrillation/diagnosis , Atrial Fibrillation/etiology , Atrial Fibrillation/physiopathology , Atrial Fibrillation/surgery , Atrial Premature Complexes/complications , Atrial Premature Complexes/diagnosis , Electrophysiologic Techniques, Cardiac , Female , Humans , Male , Middle Aged , Preoperative Care , Pulmonary Veins/surgery , Tachycardia, Ectopic Atrial/complications , Tachycardia, Ectopic Atrial/diagnosisABSTRACT
INTRODUCTION: Patients with paroxysmal atrial fibrillation (AF) often transition between sinus rhythm and AF. For AF to initiate there must be both a trigger and a substrate that facilitates reentrant activity. This trigger is often caused by a premature atrial contraction or focal activations within the atrium. We hypothesize that specific architectures of fibrosis alter local conduction to enable AF. METHODS AND RESULTS: Control goats (n = 13) and goats in chronic AF (for an average of 6 months, n = 6) had a high-density electrode plaque placed on the LA appendage. Conduction patterns following a premature atrial contraction, caused by an electrical stimulation, were quantified to determine regions of conduction slowing. These regions were compared to architecture, either diffuse fibrosis or regions of obstructive fibrosis, and overall fibrosis levels as determined by histology from the mapped region. The chronic AF goats had more obstructive fibrosis than the controls (17.5 ± 8.0 fibers/mm(2) vs. 8.6 ± 3.0 fibers/mm(2)). Conduction velocity of the AF goats was significantly slowed compared to the control goats in the transverse direction (0.40 ± 0.04 m/s vs. 0.53 ± 0.15 m/s) but not in the longitudinal direction (0.70 ± 0.27 m/s vs. 0.76 ± 0.18 m/s). CONCLUSIONS: AF-induced atrial remodeling leads to increased obstructive fibrosis and conduction velocity slowing transverse to fiber orientation following premature stimuli. The decrease in conduction velocity causes a decrease in the cardiac wavelength, and increases the likelihood of reentry and AF onset.