Effects of flecainide on the atrial defibrillation threshold.
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Atrial Fibrillation↗
Biomedical subjects
K I Lie
Publications and source records attributed to K I Lie.
Percutaneous coronary angioplasty of large venous graft using peripheral dilatation catheter.
The maximum inflated diameters of standard percutaneous transluminal coronary angioplasty (PTCA) balloon catheters can be insufficient if stenoses in oversized venous grafts are to be dilated. As an alternative to the recently described "hugging balloon" technique, it seems feasible to use a standard peripheral angioplasty (PTA) catheter with a balloon diameter that is matching to the vessel. Such a procedure calls for a free long-wire exchange and may be hampered by the stiffness of a PTA catheter. We report a case where this technique, used in an emergency procedure, resulted in a satisfactory angiographic result without causing complications.
Angioplasty, Balloon↗
Flecainide acetate in the treatment of supraventricular tachycardias: value of programmed electrical stimulation for long-term prognosis.
Twenty patients with recurrent symptomatic supraventricular tachycardia were studied to estimate the efficacy of flecainide in the long-term treatment of these arrhythmias and to evaluate the prognostic value of programmed electrophysiologic stimulation. All patients had their arrhythmia inducible at baseline evaluation. Nine patients had a Wolff-Parkinson-White (WPW) syndrome, five had a concealed bypass tract, and two had dual atrioventricular (AV) nodal pathways. In the remaining patients there was an intraatrial reentry circuit. Previous medication was no to five antiarrhythmic drugs (mean 2.4 drugs). At baseline, a circus movement tachycardia was induced in 12, AV nodal tachycardia was induced in two, atrial tachycardia was induced in three, atrial fibrillation was induced in five, and a flutter was induced in two patients. After flecainide, 2 mg/kg intravenously in 10 minutes, six patients no longer had their arrhythmia inducible. In the WPW patients, atrial fibrillation was no more inducible. In 65% of the patients there was no recurrence during a follow-up period of 11 +/- 10 months. None of the six patients who no longer had their arrhythmia inducible had a recurrence of the tachycardia over a period of up to 3 years. Seven of the other 14 patients (who still had their arrhythmia inducible) had a recurrence of the tachycardia. Positive and negative predictive values are 50% and 100%, respectively. We conclude that flecainide prevents recurrences of supraventricular tachycardias in 65% of patients with inducible supraventricular tachycardias during a mean follow-up of 11 months. Programmed electrical stimulation has a high negative predictive value in this setting. Flecainide is especially effective in preventing atrial fibrillation in patients with WPW syndrome.
Adult↗
Acute and chronic effects of ramipril and captopril in congestive heart failure.
We studied the acute and long-term effects of ramipril and captopril in 12 patients with moderate to severe congestive heart failure using an open, parallel design. Drug doses were titrated. Compared with baseline values, maximal haemodynamic and humoral effects after the first dose of both angiotensin converting enzyme inhibitors were similar, but the effects of ramipril (5 mg) demonstrated a slower onset of action and a significantly longer duration than captopril (12.5 mg). After 3 months of treatment a single dose of 5 mg ramipril showed the same 24-hour haemodynamic profile as after the first dose, but the hypotensive effect was less marked. There was no plasma accumulation of ramiprilat. Serum creatinine and potassium remained stable, except for one patient whose renal function deteriorated on captopril treatment. Complex ventricular arrhythmias occurred in 11 patients and were unaffected after treatment with ramipril or captopril. Two patients died suddenly during ramipril therapy and one patient during captopril therapy. In summary, ramipril is an effective, long-acting angiotensin converting enzyme inhibitor, producing long-term haemodynamic effects in patients with congestive heart failure. Using an individualised dosage scheme, neither long-lasting hypotension nor deterioration of renal function occurred. No effect on ventricular arrhythmias was seen.
Aged↗
Sustained-release diltiazem versus metoprolol in stable angina pectoris.
The efficacy of sustained-release diltiazem (diltiazem-SR) 120 mg b.i.d. was compared with metoprolol 100 mg b.i.d. in 12 patients with stable angina. Following a 1-week placebo period, patients received diltiazem-SR or metoprolol in two 3-week treatment periods, in a randomized double-blind crossover design. Total exercise time was increased more with diltiazem-SR than with metoprolol (1.2 min vs 0.4 min, P = 0.02), although the reduction in frequency of weekly anginal attacks was equal with both drugs (5 +/- 3 with placebo to 1 +/- 1 with both drugs). The difference between diltiazem-SR and metoprolol may, in part, be due to the fact that the tests were performed 12 h after drug administration. The diltiazem plasma levels were in the therapeutic range; metoprolol plasma levels, in contrast, were all below the therapeutic range. In addition, the patients might be tired out earlier during beta-blockade therapy, because a greater increase in exercise time with diltiazem-SR compared with metoprolol was found in those patients in whom the exercise endpoint changed from angina to fatigue. Thus, diltiazem-SR effectively reduces the frequency of anginal attacks when given twice daily, and improves exercise capacity to a greater extent than metoprolol 12 h after last dose.
Adult↗
Efficacy of felodipine in congestive heart failure.
The efficacy of felodipine, a vasodilating calcium antagonist, was analysed in 23 patients with congestive heart failure, New York Heart Association class III, during an 8-week, double-blind, randomized, placebo-controlled, parallel study. After felodipine, exercise duration increased significantly without changes in oxygen consumption. Heart rate, arterial pressures and rate pressure product decreased at similar submaximal exercise levels. Invasive haemodynamics before and after 8 weeks of therapy revealed arterial vasodilation without reflex tachycardia and no significant reduction in right atrial, pulmonary and capillary wedge pressures. Subjective symptom scores improved and side-effects were minor. Fluid retention, as assessed by body weight and ankle circumference did not occur. Felodipine has a beneficial effect in patients with moderately severe heart failure. Further research is necessary to demonstrate its long-term efficacy and safety.
Aged↗
Flecainide versus quinidine in the prevention of paroxysms of atrial fibrillation.
We compared the efficacy of flecainide versus quinidine in preventing paroxysms of atrial fibrillation in a randomized open crossover study. Twenty-six patients with weekly attacks of atrial fibrillation during the last 3 months, objectified by 24-h holter monitoring or 12-lead electrocardiogram (ECG) were treated for a period of 3 months with flecainide 100 mg b.i.d. or quinidine 500 mg b.i.d. Efficacy was assessed by 24-h holter monitoring and a questionnaire at the end of each month. Dosage was adjusted to flecainide 100 mg t.i.d. or quinidine 500 mg t.i.d. if patients still had symptomatic paroxysms of atrial fibrillation according to a questionnaire or on holter monitoring. In 46% of the patients, flecainide 100 mg b.i.d. caused total abolition of supraventricular tachycardia; after dose adjustment it caused 50% total abolition. For quinidine, the figures are 16% (p less than 0.05) and 32% (NS), respectively. Side effects occurred with flecainide only after dose adjustment (23%), but on quinidine they occurred before (8%) and after dose adjustment (20%). We conclude that flecainide suppresses paroxysms of atrial fibrillation significantly more often as compared with quinidine in the lower dosage regimen. Optimal treatment dosage of flecainide is 100 mg b.i.d. After quinidine dose adjustment, the difference in efficacy is no longer significant. However, side effects necessitating discontinuation of quinidine developed in 20% of the patients as compared to none in patients treated with flecainide 100 mg b.i.d.
Adult↗
Plasma concentration-effect relationship of felodipine intravenously in patients with congestive heart failure.
The pharmacodynamics of felodipine were analyzed in patients with congestive heart failure in a randomized, double-blind, placebo-controlled study. Felodipine at a dose of 1 mg (n = 11) or placebo (n = 12) was given intravenously during a 60-min period. Hemodynamic measurements and plasma samples were obtained every 15 min during a 2-hour period. An increase in heart rate (HR, +8%, p less than 0.01) and cardiac output (CO, +36%, p less than 0.001), and a decrease in mean arterial pressure (MAP, -24%, p less than 0.001) and systemic vascular resistance (SVR, -46%, p less than 0.001), were found. Pulmonary artery, right atrial, wedge pressure, and stroke-work index did not change. Linear regression analysis showed a significant correlation between felodipine plasma levels and changes in HR (r = 0.71, p less than 0.05), MAP (r = 0.94, p less than 0.01), CO (r = 0.73, p less than 0.05), and SVR (r = 0.88, p less than 0.01). A strong hyperbolic correlation was demonstrated between individual plasma levels and changes in MAP (r = 0.97, p less than 0.001). Hysteresis analysis showed that plasma levels are directly related to the concentration at the receptor site. A clockwise hysteresis was found in HR, CO, and SVR, but not in MAP. It is concluded that changes in flow and resistance are based on a physiological adjustment, a baroreflex-mediated response to vasodilation induced by felodipine, resulting in MAPs that remain closely related to felodipine plasma levels over a wide range.
Aged↗
Electrophysiological properties of isradipine (PN200-110) in humans.
Isradipine (PN 200-110) is a new dihydropyridine calcium-entry blocker with powerful vasodilating properties. Therapeutic concentrations do not affect myocardial contractility. However, in vitro studies have demonstrated at higher concentrations negative chronotropic action with only minor dromotropic influence. For this reason we studied the effect of intravenous isradipine (0.3 microgram/kg/min during 30 min) on sinus node and atrioventricular (AV) nodal function in 25 patients. Nine of these patients had normal sinus node function (group I), nine patients were treated with a beta blocker (group II), and seven patients had a sick sinus syndrome (group III). Mean supine arterial blood pressure decreased in all groups; however, in group I not significantly. Spontaneous sinus cycle length decreased significantly in all groups. In none of the patients effective refractory periods of atrium or ventricle were depressed. QRS duration was not significantly affected in any of the groups. There was only a slight, but significant, prolongation of the QTc of maximal 4% (except in group III). We concluded that isradipine has no depressant effect on sinus and AV nodal function in humans, not even in the presence of beta blockade or impaired sinus node function.
Adult↗
Transient complete AV block in Lyme disease. Electrophysiologic observations.
The findings in a patient with complete AV block and intra-atrial conduction disturbances due to Lyme disease are presented. The electrocardiographic follow-up and serial EP findings suggest that complete AV block in Lyme disease may signify a more extensive affection of the AV conduction system (with eventually attendant intra-atrial conduction disturbances) than described in earlier reports. An almost complete resolution of the considerable damage to the conduction system occurred within two weeks.
Adult↗
Supraventricular tachycardia mimicking ventricular tachycardia during flecainide treatment.
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Aged↗
Mortality reduction in ISIS-2 too optimistic because of unstable angina?
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Angina Pectoris↗
Noninvasive measurement of right ventricular systolic pressure by combined color-coded and continuous-wave Doppler ultrasound.
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Adult↗
Abnormal pharmacokinetics of flecainide in a "nonresponder".
Flecainide is well absorbed after oral administration. Following rapid infusion of flecainide, there is a short distribution phase. Plasma levels of flecainide are proportional to dose. Both QRS durations and flutter wave intervals are lengthened after flecainide administration. We report an abnormal pharmacokinetic response to oral as well as intravenous flecainide in a patient who was treated with flecainide for several episodes of atrial flutter. In contrast to the usual pattern, this patient did not show a significant increase in QRS duration, flutter wave interval, or plasma concentration. We could not explain this abnormal pharmacokinetic response, but excluded a rapid and complete renal clearance, an excessively high rate of metabolization, and an abnormal binding mechanism as possible mechanisms. We concluded that flecainide may produce abnormal pharmacokinetic mechanisms, preventing appearance of unbound substance in plasma, thereby preventing occurrence of electrophysiological effects.
Administration, Oral↗
Digoxin-felodipine interaction in patients with congestive heart failure.
A possible interaction between felodipine and digoxin was studied in 23 patients with congestive heart failure before and after 8 weeks treatment with both drugs. A modest, non-significant increase in serum digoxin level 2 h postdose (+15%) was found in the felodipine group (n = 11) compared to placebo (n = 12), with no change in the trough and 6 h postdose levels. There was a bimodal distribution of the observed changes in serum digoxin level 2 h postdose: a significant increase (p less than 0.001) was observed only in patients with a high plasma felodipine level, which may have been caused by changes in the absorption rate in those patients. Changes in the elimination of digoxin after felodipine therapy appeared unlikely, since the trough and 6 h post-dose levels were unchanged. Analysis of the clinical characteristics, haemodynamics and laboratory values revealed no significant differences between the subgroups. The observed increase in serum digoxin warrants monitoring the trough and peak levels digoxin in patients with congestive heart failure who are also being treated with felodipine.
Aged↗
Successful use of flecainide in atrial fibrillation with rapid ventricular rate in the Wolff-Parkinson-White syndrome.
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Adult↗
Value of New York Heart Association classification, radionuclide ventriculography, and cardiopulmonary exercise tests for selection of patients for congestive heart failure studies.
To evaluate the necessity of an objective cardiopulmonary exercise test in the selection procedure of patients for heart failure studies, 50 patients with congestive heart failure New York Heart Association (NYHA) class II and III and a left ventricular ejection fraction less than 40% were subjected to a cardiopulmonary exercise test. The results of the exercise test were compared with the independent clinical estimation of NYHA class and data of measurements obtained at rest. The NYHA classification separated the patients with a mild to moderate impairment of aerobic capacity from patients with a moderate to severe impairment of aerobic capacity very well, but 32% of the NYHA class II patients had a near normal aerobic capacity, and 29% of the NYHA class III patients had a very severe impairment of aerobic capacity, more compatible with NYHA class IV. Only data from exercise measurements showed differences between groups. The determination of maximal aerobic capacity for an objective assessment of patients' performance at exercise is necessary for a proper selection procedure of patients for heart failure studies.
Adult↗
The size of infarction as judged enzymatically in 1974 patients with acute myocardial infarction. Relation with symptomatology, infarct localization and type of infarction.
A common data base of six coronary care units containing personal and clinical data of 17462 patients was used to investigate the relation between clinical symptoms of patients with acute myocardial infarction and size of infarction. In 1974 of the 5110 patients, in whom a final diagnosis of infarction was made, size of infarction was determined according to serially measured levels of serum alpha-hydroxybutyrate dehydrogenase. The episode of infarction was the first in 1396 patients, was recurrent in 497, and undetermined in 81 patients. We calculated the size factor (defined as the mean size of infarction of patients with a particular symptom divided by the mean size of infarction of patients without that symptom) to evaluate the role of the size of infarction to manifestation of certain clinical symptoms. Bradycardia, shock and right-sided failure when noted on admission to the coronary care unit, had factors for size of infarction significantly greater than 1.0 (1.15, 1.79 and 1.30, respectively) in patients suffering an initial infarction, but not significantly different from 1.0 in patients with recurrent infarction. The occurrence of primary and secondary ventricular tachycardia and/or fibrillation, left heart failure (Killip class II-IV), symptomatic supraventricular tachycardia, high-degree atrioventricular blocks, ruptures and death in the coronary care unit was associated with factors significantly greater than 1.0 in those patients having both initial and recurrent infarctions. The size of infarction as judged enzymatically was significantly larger in patients with anterior than inferior and lateral infarction. The size of infarctions without Q waves was judged to be generally 35% smaller than infarctions producing Q waves. It is concluded that the size of infarction determines the occurrence of several symptoms and complications diagnosed at admission or during stay in the coronary care unit.
Adult↗