Gabriele Bronzetti

Favorable effects of flecainide in transvenous Internal cardioversion of atrial fibrillation

OBJECTIVES The aim of the study was to evaluate the effects of intravenous (IV) flecainide on defibrillation energy requirements in patients treated with low-energy internal atrial cardioversion. BACKGROUND Internal cardioversion of atrial fibrillation is becoming a more widely accepted therapy for acute episode termination and for implantable atrial defibrillators. METHODS Twenty-four patients with atrial fibrillation (19 persistent, 5 paroxysmal) underwent elective transvenous cardioversion according to a step-up protocol. After successful conversion in a drug-free state, atrial fibrillation was induced by atrial pacing; IV flecainide (2 mg/kg) was administered and a second threshold was determined. In patients in whom cardioversion in a drug-free state failed notwithstanding a 400- to 550-V shock, a threshold determination was attempted after flecainide. RESULTS Chronic persistent atrial fibrillation was converted in 13/19 (68%) patients at baseline and in 16/19 (84%) patients after flecainide. Paroxysmal atrial fibrillation was successfully cardioverted in all the patients. A favorable effect of flecainide was observed either in chronic persistent atrial fibrillation (13 patients) or in paroxysmal atrial fibrillation (5 patients) with significant reductions in energy requirements for effective defibrillation (persistent atrial fibrillation: 4.42+/-1.37 to 3.50+/-1.51 J, p < 0.005; paroxysmal atrial fibrillation: 1.68+/-0.29 to 0.84+/-0.26 J, p < 0.01). In 14 patients not requiring sedation, the favorable effects of flecainide on defibrillation threshold resulted in a significant reduction in the scores of shock-induced discomfort (3.71+/-0.83 vs. 4.29+/-0.61, p < 0.005). No ventricular proarrhythmia was observed for any shock. CONCLUSIONS Intravenous flecainide reduces atrial defibrillation threshold in patients treated with low-energy internal atrial cardioversion. This reduction in threshold results in lower shock-induced discomfort. Additionally, flecainide may increase the procedure success rate in patients with chronic persistent atrial fibrillation.

Efficacy and Tolerability in Fully Conscious Patients of Transvenous Low-Energy Internal Atrial Cardioversion for Atrial Fibrillation☆

Transvenous low-energy atrial cardioversion was performed in a series of fully conscious patients (30 patients with chronic atrial fibrillation and 5 patients with paroxysmal atrial fibrillation). The results show that internal atrial defibrillation is effective and tolerable in most patients.

Long-term incidence of atrial fibrillation and flutter after transcatheter atrial septal defect closure in adults

BACKGROUND The long-term risk of atrial fibrillation and flutter (AFF) after trascatheter atrial septal defects (ASD) closure in adults is unknown. METHODS We studied 134 patients who have undergone transcatheter ASD closure at our institution at an age of > 18 years (mean age 39 +/- 16 years); Patients were followed-up for 4.8 +/- 2.7 years (range 0.8-9.6 years). We assessed the presence of AFF both before and after ASD closure using standard 12 lead ECGs or 24h ambulatory Holter monitors. RESULTS 13 patients (10%) had documented AFF before the procedure (paroxysmal in 6, permanent in 7). Patients with AFF before the procedure were older (p < 0.0001), and had worse clinical condition (p = 0.0008). Patients without a history of AFF before the procedure and those who experienced paroxysmal AFF before the procedure had a very low annual risk (0%) of subsequent permanent AFF at long-term follow-up. Four patients with permanent AFF before the procedure (onset of < 12months) underwent electrical cardioversion immediately before ASD closure. Two of them (50%) are in sinus rhythm after 4.1 and 7.0 years, respectively. CONCLUSIONS Transcatheter ASD closure performed in adults with no history of AFF or with a history of paroxysmal AFF before closure seems to protect from development of AFF in the long-term. In selected patients with permanent AFF at closure, device ASD closure together with arrhythmia cardioversion might be able to restore and maintain sinus rhythm in the long-term.

Modulation of neurohormonal activity after treatment of children in heart failure with carvedilol

BACKGROUND In adults with heart failure, neurohormonal overstimulation is related to the progression of the disease, and influences prognosis. beta-blockers, which modulate neurohormonal activation, now play an essential role in the pharmacological management of heart failure in adults, but their use in children is very limited. PATIENTS AND METHODS To investigate the effects of carvedilol administration on neurohormonal activation and left ventricular function, carvedilol was added to standard treatment for heart failure in 9 patients with dilated cardiomyopathy due to heart muscle disease. Standard treatment has been in place for at least 1 month. The protocol consisted in a baseline evaluation to assess neurohormonal activation, and echocardiographic evaluation of left ventricular function. This was followed by a final evaluation at 12 months from carvedilol loading. Carvedilol was started at 0.05 mg/kg/day, and increased every two weeks until the target dose of 0.8 mg/kg/day was reached. RESULTS Carvedilol administration was associated with a significant reduction in plasma norepinephrine (p = 0.00001), dopamine (p = 0.0001), aldosterone (p = 0.00001) and activation of the renin-angiotensin system (p = 0.0006). Similar reductions in vanilmandelic and homovanillic acid were noted. After 12 months, a positive remodeling took place, with significant reductions in end-diastolic (p = 0.004) and end-systolic diameters (p = 0.009), and an increase in left ventricular ejection fraction (p = 0.001). No adverse effects needing reduction or interruption in the dosage were noted in the run-in phase, nor in the period of maintenance. CONCLUSION Carvedilol is a safe complement to standard therapy for heart failure in children, allowing a significant reduction of neurohormonal activation with evident benefits on both ventricular function and the clinical condition.

Intravenous flecainide for the treatment of junctional ectopic tachycardia after surgery for congenital heart disease

BACKGROUND Junctional ectopic tachycardia (JET) is a life-threatening arrhythmia producing severe hemodynamic dysfunction, which may complicate the postoperative course of surgery for congenital heart disease. Strict care and a fast and effective antiarrhythmic strategy are essential, because mortality largely depends on the duration of the arrhythmia. METHODS Seven consecutive neonates with postoperative JET without any evidence of myocardial ischemia received intravenous flecainide after conventional therapies proved ineffective. Atrial pacing at the minimal rate for atrioventricular synchrony was followed by a 10-min intravenous infusion of 1.6 mg/kg flecainide, then continuous infusion of 0.4 mg/kg flecainide per hour. Treatment was considered effective based on restoration of sinus rhythm or a JET rate no higher than 170 bpm within 4 hours of flecainide loading. Overall mean flecainide infusion lasted 31.2 hours (range 25 to 53 hours). Side effects were assessed by monitoring plasma flecainide levels, electrocardiogram, arterial pressure, and central venous pressure. RESULTS Flecainide was effective in all 7 patients after an infusion duration of 3.6 +/- 1.5 hours. Sinus rhythm was restored after 7.2 +/- 9.7 hours. After 4 hours of loading, heart rate fell from 219 +/- 14 to 136 +/- 7 bpm (p < 0.0001), arterial pressure increased from 69 +/- 8 to 93 +/- 10 mm Hg (p < 0.0001), while central venous pressure decreased from 8.0 +/- 1.6 to 5.2 +/- 1.9 mm Hg (p = 0.0007). No side effect or recurrence was noted. CONCLUSIONS Flecainide can exert a fast antiarrhythmic effect on postoperative JET, and its infusion can be modulated to maintain the concentration within the therapeutic range, thus avoiding toxicity. We propose further consideration of flecainide for treatment of JET in neonates without myocardial ischemia.

Role of atrial fibrillation after transcatheter closure of patent foramen ovale in patients with or without cryptogenic stroke

BACKGROUND Atrial fibrillation (AF) after transcatheter closure of patent foramen ovale (PFO) is not a rare complication. However little is known about the effect of atrial septal device implantation on the occurrence of this arrhythmia. OBJECTIVE The aim of this study was to evaluate the occurrence of AF in two groups of patients who underwent transcatheter PFO closure: those with a previous cryptogenic stroke and those with other index events respectively. MATERIALS AND METHODS Patient population included 276 patients with documented PFO who underwent percutaneous closure at our institution. Patients were grouped on the basis of two distinct clinical presentations: a) 246 patients with history of previous cryptogenic cerebrovascular ischemic event (CIE) or b) 30 patients with other different index events. AF after PFO closure was detected by 12-lead electrocardiography or by 24-h-Holter monitoring. RESULTS During a mean follow-up of 17 months, new-onset AF was documented in 10 patients (4%), all included in the group with a previous cryptogenic CIE, at a mean of 1.6 months post-procedure. Comparing patients with and without AF, age (mean 56 years vs 46 years, p = 0.012) and left atrial size (4.4 cm vs 3.7 cm, p = 0.001) resulted to differ significantly. The type and size of occluder devices do not seem to impact the occurrence of AF after PFO closure. CONCLUSION In patients presenting with cryptogenic stroke, especially in those with slightly enlarged left atria and age above 50–55 years, detection of a PFO should prompt an extended monitoring for excluding AF.

Late Improvement in Ventricular Performance Following Internal Cardioversion for Persistent Atrial Fibrillation

The aim of the study was to evaluate the time course of atrial and ventricular function improvement following internal atrial cardioversion in patients with structural heart disease. Twenty‐nine patients with chronic persistent atrial fibrillation (AF) and underlying structural heart disease were followed by serial echocardiograms performed at 1 and 6 hours, 1 day, 1, 2, and 3 weeks, and 1, 2, 3, and 6 months after successful cardioversion. Sinus rhythm was maintained at 6 months in 24 patients. Following cardioversion the time course of left atrial mechanical function (peak A wave, percent A wave filling) differed from that of left ventricular ejection fraction: peak A wave values (cm/s) increased significantly at 1 week ( 51 ± 23 vs 35 ± 15 at 1 hour, P < 0.05 ), percent A wave filling (%) increased significantly at 2 weeks ( 34 ± 12 vs 22 ± 9 at 1 hour, P < 0.05 ), whereas left ventricular ejection fraction (%) increased later (at 1 month 60 ± 14 vs 55 ± 14 at baseline, P < 0.05 and at 2 months 60 ± 14 vs 56 ± 14 at 1 hour, P < 0.05 ). In conclusion, restoration of sinus rhythm results in an improvement in left ventricular ejection fraction during follow‐up, even in patients with structural heart disease without fast ventricular rates at baseline. The dissociation between the time course of atrial and ventricular function improvement suggests that the latter was partly due to regression of a concealed form of cardiomyopathy and/or of a ventricular dysfunction due to chronic AF. (PACE 2003; 26:1218–1226)

Neurocardiogenic Syncope in Selected Pediatric Patients—Natural History during Long-Term Follow-Up and Effect of Prophylactic Pharmacological Therapy

AbstractObjective: The natural history of pediatric patients with severely symptomatic neurocardiogenic syncope is poorly defined respect to the likelihood of remission or symptomatic recurrence along time. We undertook this study to investigate the likelihood of clinical relapse, and to assess the effect of prophylactic pharmacological treatment in the most symptomatic patients. Methods: Twenty-nine patients with neurocardiogenic syncope were studied at our Institution: 14 (12 ± 3.6 years) highly symptomatic received prophylactic therapy with β-blockers guided by head up tilt (HUT), whereas 15 (12.2 ± 2.7 years) moderately symptomatic received only education to avoid triggering of the vasovagal reflex and to abort forthcoming syncope. Patients were then followed respectively for 33.7 ± 9.0 and 33.3 ± 8.7 months (p = NS). Results: The average duration of symptoms before HUT was 9.0 ± 4.3 months (range 3–17) for treated patients, and 6.2 ± 2.5 months (range 2–11) for those untreated ( p < 0.05). Treated patients had also a greater number of symptomatic events: 6 ± 2 vs. 2 ± 1 (p < 0.001). During follow up, 9/15 untreated and 6/14 treated patients had at least 1 recurrence, with an odds ratio of 2 (95% CI 0.72–5.49). Clinical events were greatly reduced in both groups at follow up, but treated patients had a significantly greater reduction either of syncopal (p < 0.001) or near syncopal events (p < 0.02). Time to the first recurrence, syncope or near syncope, was shorter for untreated vs treated patients: 5 ± 2 vs. 25 ± 12 months (p < 0.001). Looking at the time course of all clinical recurrences, 23/26 occurred in untreated patients, whereas 7/10 occurred in treated patients within 24 months. An attempt to therapy discontinuation was made after 30 months in 4 patients, and resulted in half of them being asymptomatic, and half with a single minor recurrence. Conclusions: Spontaneous reduction of symptoms occurs along time in pediatric patients with neurocardiogenic syncope, so that recurrences are very unlikely after 24 months from first diagnosis. Tiered prophylactic therapy may be guided by HUT in selected highly symptomatic patients; β-blockers appear a very effective intervention. Larger, prospective controlled studies are required to investigate the role of any intervention in moderately symptomatic patients.

Incompatibility between intravenous amiodarone and heparin in an infant

Amiodarone is an effective antiarrhythmic agent and represents the drug of choice in the treatment of severe arrhythmias, especially in the setting of ventricular dysfunction. Amiodarone has the potential for interaction with many cardiac and non-cardiac drugs. Nonetheless few incompatibilities have been reported. We report the incompatibility between amiodarone and heparin administrated in the same vein in a case of a one month old baby with atrial flutter. This topic needs more attention, due to the frequent co-administration of these two drugs in tachyarrhythmias with high thromboembolic risk.

The Seven “S” Murmurs: An Alliteration About Innocent Murmurs in Cardiac Auscultation

Cardiac murmurs are a frequent finding of physical examinations, but most of them are innocent. Nevertheless, the discovery of a murmur may provoke significant parental anxiety. Up to 50% of children may have cardiac murmurs, but structural heart disease is present in less than 1%. Despite this reassuring epidemiology, a parent who has just been told about a murmur thinks he or she is being told about a serious disease. It is therefore crucial to discriminate between innocent murmurs and murmurs related to heart disease, in order to reduce parental apprehension and to avoid unnecessary referrals to a pediatric cardiologist. The art of auscultation requires considerable practice, and some reports indicate that the clinical auscultation skills of pediatric residents may be improved in many ways. We therefore propose the “Seven S Murmurs” to younger doctors, this being a sort of wordplay, an alliteration, designed to help them keep the semiotic aspects of a potentially innocent murmur in mind. Seven is a highly symbolic number in many fields, from literature to religion, and from astronomy to mythology. In cardiology, we have 7 types of innocent murmurs (Still’s murmur, innocent pulmonary blood flow murmur, innocent pulmonary branch murmur of the infant, supraclavicular bruit, venous hum, mammary souffle, and cardiorespiratory murmur). The 7 Ss that help us recall these innocent murmurs are the following: Systolic (apart from “venous hum,” a diastolic murmur is always pathological), Small (limited to a small area), Soft (the amplitude is low), Short (in duration, it never being olosystolic), Single (not accompanied by clicks or gallop), Sweet (never harsh), and Sensitive (to posture or breathing). In the Mordecai Richler novel Barney’s Version, the protagonist Barney Panofsky is often obsessed with remembering the names of the Seven Dwarfs. Frustrated at being unable to remember more than 4 or 5 of them, he calls his son overseas to find out the names of the ones he is missing. Likewise, even experienced pediatricians may sometimes find it a challenge to remember all 7 signs, but now they will be able to summon a junior doctor to help.