Human atrial natriuretic peptide infusion for a neonate with congestive heart failure after total correction of total anomalous pulmonary venous connection.
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A successful case of human atrial natriuretic peptide (HANP) infusion therapy for a neonate who developed congestive heart failure (CHF) after total repair of total anomalous pulmonary venous connection was performed on the first day of life. Following 14h of HANP infusion at incremental doses of 0.125-0.25 microg x kg(-1) x min(-1) urine output and hemodynamics dramatically improved. Urine output increased from 1.1 to 10.6 ml/h (p<0.0001) and good urinary output (13.0 ml/h) was maintained even after discontinuation of the infusion. During the infusion, the heart rate decreased from 166 to 152 beats/min (p<0.0001), and the systemic systolic blood pressure increased from 82 to 103 mmHg (p<0.0001). Central venous pressure was not significantly affected by HANP infusion. This is the first successful case of HANP infusion therapy as the first treatment of post-operative pulmonary hypertension in this age group. This therapy can be used safely and may be useful in neonates with CHF resulting from other causes, but more investigation is needed. (+info)
Effect of phenylephrine on focal atrial fibrillation originating in the pulmonary veins and superior vena cava.
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OBJECTIVES: This study was aimed at evaluating the effects of phenylephrine infusion on the occurrence of focal atrial fibrillation (AF). BACKGROUND: Paroxysmal AF can be initiated by ectopic atrial beats originating in the pulmonary vein (PV) or superior vena cava (SVC). The effect of change in autonomic tone on this focal AF is unknown. METHODS: This study included 12 patients with frequent bursts of AF documented by 24-h Holter monitoring. The number and coupling interval of spontaneous ectopic activity and bursts of AF were evaluated for 1 min before and after phenylephrine (2 to 3 microg/kg) injection. RESULTS: After detailed mapping, four patients had a focus located in the left superior PV, six in the right superior PV and two in the SVC. In 10 patients with AF foci originating in the PVs, the frequency of ectopic activity (19.5 +/- 27.4 vs. 11.4 +/- 22.9 beats/min, p = 0.059) was reduced as well as AF bursts (14 +/- 3 vs. 1.8 +/- 2.7 bursts/min, p = 0.005) before versus after phenylephrine injection; the minimal coupling interval of ectopic activity and AF bursts became longer compared with baseline. The maximal percent increase in sinus cycle length after phenylephrine injection was significantly greater in patients with complete suppression of AF compared with those with partial suppression (43 +/- 19 vs. 14 +/- 5%, p = 0.01). However, no significant effect of phenylephrine on AF originating in the SVC was found. CONCLUSIONS: Change in autonomic tone induced by phenylephrine injection was effective in suppressing focal AF originating in the PVs but not in the SVC. (+info)
Prognostic value of pulmonary venous flow Doppler signal in left ventricular dysfunction: contribution of the difference in duration of pulmonary venous and mitral flow at atrial contraction.
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OBJECTIVES: We assessed the contribution of difference in duration of pulmonary venous and mitral flow at atrial contraction (ARd-Ad) for prognostic stratification of patients with left ventricular (LV) systolic dysfunction. BACKGROUND: Although pulmonary venous flow (PVF) variables may supplement mitral flow patterns in evaluating left ventricular (LV) diastolic function, their value to the prognostic stratification of patients has not been investigated. METHODS: Pulsed wave Doppler mitral and PVF velocity curves were recorded in 145 patients (mean age: 70 years) with LV systolic dysfunction secondary to ischemic or nonischemic cardiomyopathy who were followed for 15 +/- 8 months. In 38% of patients, PVF signal was enhanced by the intravenous (IV) administration of a galactose-based echo-contrast agent. Based on E-wave deceleration time < or = or >130 ms and ARd-Ad, patients were grouped into restrictive (group 1, n = 40), nonrestrictive with ARd-Ad > or =30 ms (group 2, n = 55) and nonrestrictive with ARd-Ad <30 ms (group 3, n = 50). RESULTS: During follow-up, 29 patients died from cardiac causes and 28 were hospitalized for worsening heart failure (HF). On multivariate Cox model, ARd-Ad > or =30 ms provided important prognostic information with regard to cardiac mortality and emerged as the single best predictor of cardiac events (cardiac mortality, hospitalization). The 24-month cardiac event-free survival was best (86.3%) for group 3; it was intermediate (37.9%) for group 2; and it was worst (22.9%) for group 1 (p < 0.0002 group 1 vs. 3; p < 0.0005 group 2 vs. 3; p < 0.0003 group 1 vs. group 2). CONCLUSIONS: Assessment of ARd-Ad exhibited an independent value in the prognostic evaluation of patients with LV systolic dysfunction. Moreover, it contributed to identify patients at low, intermediate and high risk of cardiac events. (+info)
First human experience with pulmonary vein isolation using a through-the-balloon circumferential ultrasound ablation system for recurrent atrial fibrillation.
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BACKGROUND: Standard mapping and ablation of focal sources of atrial fibrillation are associated with very long procedure times and low efficacy. An anatomic approach to complete pulmonary vein isolation could overcome these limitations. METHODS AND RESULTS: Fifteen patients with atrial fibrillation refractory to medication underwent circumferential isolation of the pulmonary veins by using a novel catheter, with an ultrasound transducer (8-MHz) mounted near the tip, in a saline-filled balloon. Twelve atrial foci and/or atrial fibrillation triggers were identified in 9 patients (pulmonary vein locations: left upper, 3; right upper, 6; right middle, 1; right lower, 1; and left inferior, 1). In 5 patients, lesions were placed in the absence of any mapped triggers. Irrespective of trigger mapping, circumferential isolation of both upper pulmonary veins was attempted in all patients. The lower pulmonary veins were ablated when sinus rhythm activation mapping revealed evidence of a sleeve of atrial muscle in the vein. The median number of lesions per patient required to isolate 1 pulmonary vein was 4 (range, 1 to 29). After ablation, no evidence of narrowing was seen with repeat venography or follow-up computed tomography scan. After a mean follow-up of 35+/-6 weeks, 5 patients had recurrence of atrial fibrillation. Three responded to drugs that were previously ineffective, and 2 remained in atrial fibrillation. CONCLUSIONS: This novel ultrasound ablation system can successfully isolate multiple pulmonary veins. At early follow-up, this approach seems to be effective in preventing recurrent atrial fibrillation in a significant number of patients. (+info)
Arrhythmogenic activity of cardiac muscle in pulmonary veins of the dog: implication for the genesis of atrial fibrillation.
(61/1323)
OBJECTIVE: Pulmonary veins are important foci of ectopic beats to initiate paroxysmal atrial fibrillation. The purpose of this study were to investigate the electrophysiological characteristics of excitable cells in canine pulmonary veins obtained from healthy and chronic rapid atrial pacing dogs and their responses to cardioactive agents. METHODS: Transmembrane action potentials (APs) were recorded from multiple sites of pulmonary veins isolated from 17 healthy dogs and 14 dogs with chronic (6-8 weeks) rapid atrial pacing (780 bpm). RESULTS: In normal superfusate, several types of electrical activities were identified, including silent electrical activity, fast response APs driven by electrical stimulation, and spontaneous fast or slow response APs (with or without early afterdepolarizations). The incidences of AP with an early afterdepolarization (93% versus 41%) was greater in chronic pacing dogs. The spontaneous activities were depressed by beta-adrenoceptor blocker, calcium channel blocker, adenosine and acetylcholine. High frequency (>8 Hz) irregular rhythms occurred spontaneously or were induced by cardioactive agents or electrical stimuli. The incidence of spontaneously occurring tachyarrhythmias was much higher in preparations from chronic pacing dogs (93%) than from control (12%). The tachyarrhythmias were suppressed by sodium channel blocker, potassium channel blocker or magnesium. CONCLUSIONS: Pulmonary veins have arrhythmogenic ability through spontaneous activities or high-frequency irregular rhythms. The higher incidence of spontaneously occurring high-frequency irregular rhythms in chronic rapid atrial pacing dogs may account for the increased risk of atrial fibrillation in these dogs. (+info)
Electrophysiological breakthroughs from the left atrium to the pulmonary veins.
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BACKGROUND: The extent of ostial ablation necessary to electrically disconnect the pulmonary vein (PV) myocardial extensions that initiate atrial fibrillation from the left atrium has not been determined. METHODS AND RESULTS: Seventy patients underwent PV mapping with a circumferential 10-electrode catheter during sinus rhythm or left atrial pacing. After assessment of perimetric distribution and activation sequence of PV potentials, ostial ablation was performed at segments showing earliest activation, with the end point of PV disconnection. A total of 162 PVs (excluding right inferior PVs) were ablated. PV potentials were present at 60% to 88% of their perimeter, but PV muscle activation was always sequential from a segment with earliest activation (breakthrough). Radiofrequency (RF) application at this breakthrough eliminated all PV potentials in 34 PVs, whereas a secondary breakthrough required RF applications at separate segments in 77; in others, >2 segments were ablated. A median of 5, 6, and 4 bipoles from the circular catheter were targeted in the right superior, left superior, and inferior PVs, respectively, to achieve PV disconnection. Early recurrence of arrhythmia was observed in 31 patients as a result of new venous or atrial foci or recovery of previously targeted PVs, most related to a single recovered breakthrough that was reablated with local RF application. CONCLUSIONS: Although PV muscle covers a large extent of the PV perimeter, there are specific breakthroughs from the left atrium that allow ostial PV disconnection by use of partial perimetric ablation. (+info)
A novel method for transcatheter closure of atrial septal defect within an aneurysm of the fossa ovalis: double sheath technique.
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An aneurysm of the fossa ovalis is frequently associated with an atrial septal defect. Intervention with transcatheter closure of such defects may be difficult since it bears the risk of inadvertent deployment of the device with both umbrellas in the right or left atrium. A novel technique for the closure of such multiperforated aneurysms of the fossa ovalis, which allows central positioning and controlled deployment of the device, is reported. (+info)
Circumferential radiofrequency ablation of pulmonary vein ostia: A new anatomic approach for curing atrial fibrillation.
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BACKGROUND: The pulmonary veins (PVs) and surrounding ostial areas frequently house focal triggers or reentrant circuits critical to the genesis of atrial fibrillation (AF). We developed an anatomic approach aimed at isolating each PV from the left atrium (LA) by circumferential radiofrequency (RF) lesions around their ostia. METHODS AND RESULTS: We selected 26 patients with resistant AF, either paroxysmal (n=14) or permanent (n=12). A nonfluoroscopic mapping system was used to generate 3D electroanatomic LA maps and deliver RF energy. Two maps were acquired during coronary sinus and right atrial pacing to validate the lateral and septal PV lesions, respectively. Patients were followed up closely for >/=6 months. Procedures lasted 290+/-58 minutes, including 80+/-22 minutes for acquisition of all maps, and 118+/-16 RF pulses were deployed. Among 14 patients in AF at the beginning of the procedure, 64% had sinus rhythm restoration during ablation. PV isolation was demonstrated in 76% of 104 PVs treated by low peak-to-peak electrogram amplitude (0. 08+/-0.02 mV) inside the circular line and by disparity in activation times (58+/-11 ms) across the lesion. After 9+/-3 months, 22 patients (85%) were AF-free, including 62% not taking and 23% taking antiarrhythmic drugs, with no difference (P:=NS) between paroxysmal and permanent AF. No thromboembolic events or PV stenoses were observed by transesophageal echocardiography. CONCLUSIONS: Radiofrequency PV isolation with electroanatomic guidance is safe and effective in either paroxysmal or permanent AF. (+info)