[Verapamil-responsive ventricular tachycardia in small children: a case report and review of the literature]

A case of verapamil-responsive incessant ventricular tachycardia in a 4-year-old girl is reported. Oral verapamil alone failed in maintaining stable sinus rhythm. With association of oral verapamil and betablockers (nadolol) the patient remained asymptomatic without recurrence of ventricular tachycardia over a follow-up of 1 year. In case of failure of monotherapy with verapamil or betablockers alone, an association of both can be effective and safe also in pediatric age. Radiofrequency catheter ablation should be reserved, especially in pediatric age, only to patients with impaired ventricular function who are not responsive to medical therapy.

Effects of long-term vasodilator therapy in patients with carotid sinus hypersensitivity

BACKGROUND

In patients affected by carotid sinus hypersensitivity, long-term vasodilator therapy might increase the risk of syncopal episodes by reducing systolic blood pressure and venous return to the heart.

METHODS AND RESULTS

Thirty-two patients (mean age 73 +/- 9 years; 20 men) who met all the following criteria were included: (1) one or more episodes of syncope occurring during long-term (>6 months) treatment with angiotensin-converting enzyme inhibitors, long-acting nitrates, calcium antagonists, or a combination of these; (2) a positive response to carotid sinus massage, defined as the reproduction of spontaneous syncope in the presence of ventricular asystole > or =3 seconds or a fall in systolic blood pressure > or =50 mm Hg; (3) negative workup for other causes of syncope. The patients were randomly assigned to continue or to discontinue use of vasodilators; carotid sinus massage was repeated 2 weeks after randomization. By the end of the study period, the baseline values of systolic blood pressure were significantly different between the 2 groups of patients both in supine (P=.01) and upright (P=.03) positions. Syncope had been induced by carotid sinus massage in 81% of patients in the "on-vasodilator" group and in 62% of patients in the "off-vasodilator" group (P=.21). The cardioinhibitory reflex was of similar magnitude in the 2 groups, being found in 50% of the patients in each group, with a maximum ventricular pause of 7.1 +/- 2.7 and 6.7 +/- 1.8 seconds, respectively. The percentage decrease of blood pressure did not differ between the 2 groups, even if, in absolute values, the baseline difference of blood pressure roughly persisted for the duration of the test. In consequence of that, the rise of blood pressure to similar values was delayed approximately 30 seconds in the "on-vasodilator" group and took more than 2 minutes to return to baseline values.

CONCLUSIONS

In patients affected by carotid sinus hypersensitivity, chronic vasodilator therapy does not have a direct effect on carotid sinus reflexivity, although the delayed recovery of pretest blood pressure values could indirectly potentiate the severity of the clinical manifestations of the syndrome. The persistence of hypotension for a longer time after the end of the massage suggests that vasodilators cause an impairment of compensatory mechanisms.

Pheochromocytoma crisis caused by contemporary ergotamine, caffeine, and nimesulide administration

Pheochromocytoma is a rare tumor that secretes excess catecholamines. Pheochromocytoma crises may be precipitated by the use of several drugs. This article describes the case of a patient affected by pheochromocytoma in whom multiple organ failure developed after contemporary administration of ergotamine, caffeine, and nimesulide. The patient recovered completely long after surgical intervention.

[Unstable angina in coronary intensive care units without hemodynamics: is admissible a strategy limiting the indications for coronarography?]

In coronary care units (CCU) without cardiac catheterization facilities, coronary angiography is rarely carried out when a successful medical treatment in the acute phase of unstable angina has been obtained. However, the unstable angina still has an uncertain prognosis when the remission of pain is obtained with drugs. This study presents a follow-up of 147 consecutive patients (aged 66.8 +/- 10.4 years) admitted to our CCU in 1991 and 1992 for unstable angina; 33 of them (22.4%) were in Braunwald class I. 2 (1.4%) in class II and 112 (76.2%) in class III. The patients were treated according to the usual therapy protocols and class III patients received i.v. heparin. In selected cases we used thrombolysis (10 patients) and intra-aortic balloon pump (5 patients). During hospitalization 1 patient died (0.7%), 5 patients (3.4%) suffered an acute myocardial infarction and 9 patients (6.1%) had angina. Stabilization of unstable angina was achieved in 132 patients (89.9%): in 113 (76.8%) during the first 48 hours, and in 19 (12.9%) later. Coronary angiography was carried out in non-stabilized patients and in 46 (34.8%) of the 132 with successful treatment (Group I). Eighty-six patients, without indication to coronary angiography were discharged in medical therapy (Group II). During the follow-up (mean of 15.0 +/- 9.0 months) Group I 10 patients (18.2%) had cardiac events (death, myocardial infarction, or recurrent angina) vs 26 of Group II (p < 0.05). In Group I coronary angiography together with clinical criteria of high risk allowed the identification of candidates to coronary revascularization (61.8% of Group I patients while). These data show that the initial success of treatment during the acute phase of unstable angina should not be considered as a favourable prognostic index. Coronary angiography appears to be indicated for clinical evaluation and therapeutical decision.

[Right atrial metastasis as an initial clinical manifestation of adenocarcinoma of the colon]

We report the case of a young woman suffering from colonic mucinous adenocarcinoma with the unusual clinical presentation as a right atrial metastasis. The tumor was successfully resected, and after histopathological characterization, the primary lesion was searched for and discovered. The tumor had the clinical appearance and echocardiographic pattern of a pedunculated atrial myxoma. The aspects of echo-patterns useful for differential diagnosis are discussed.

[Efficacy of intravenous and per os propafenone in the ambulatory treatment of recent-onset atrial fibrillation]

Propafenone efficacy in conversion of atrial fibrillation to sinus rhythm has been well documented. In this study we considered propafenone efficacy according to a graduated protocol of administration. Forty-two patients with recent-onset atrial fibrillation, without left ventricular failure, ischemic symptoms and in absence of antiarrhythmical treatment, were treated according to the following protocol: propafenone 1 mg/kg i.v. (5 min) followed, in the non-responder patient group, by a second dose, 0.5 mg/kg i.v. (15 min). Patients with persistent atrial fibrillation received 900 mg/daily of propafenone per os, at home for two days. Thereafter, patients still not restored to sinus rhythm were considered non-responders. Patients who were converted to sinus rhythm received 450 mg daily of the drug (oral administration), at home, as antiarrhythmical prophylaxis, for three months. Thirty-nine patients were converted to sinus rhythm (92.8%), 24 of them after intravenous propafenone (57.2%), and the other 15 (35.6%) after oral administration of the drug. The average heart rate in patients not converted to sinus rhythm with intravenous propafenone was significantly reduced after drug administration, compared to basal values (from 136.4 +/- 18.1 to 107.1 +/- 17.6, p < 0.01), allowing home treatment. No major cardiac effects were observed after infusion, nor after oral administration of propafenone. During a three-month follow-up we observed 3 cases of relapsed atrial fibrillation and 2 discontinued treatments due to minor gastroenteric side effects. In conclusion, propafenone therapy in ambulatory regimen is safe and effective in patients with recent-onset atrial fibrillation. In many patients refractory to IV treatment, further therapeutic success may be achieved following oral propafenone administration.

Propafenone versus amiodarone in field treatment of primary atrial tachydysrhythmias

Thirty-nine patients with paroxysmal atrial fibrillation or supraventricular tachycardia randomly received amiodarone or propafenone intravenously at home. Fifteen patients received amiodarone and 24 received propafenone; 87.5% of the patients who received propafenone and 40% of the patients who received amiodarone were converted at home to sinus rhythm (P less than .005). The median time of conversion was 10 minutes (range 5 to 35) for propafenone and 60 minutes (range 20 to 130) for amiodarone (P less than 0.005). When either drug failed to terminate atrial tachydysrhythmias at home, the same drug always restored sinus rhythm with subsequent oral treatment during hospitalization. No major side effects were observed after the infusion of either drug. The incidence of minor side effects was not significantly different between the two drugs. Both the drugs are efficacious and safe in the acute management of primary supraventricular tachydysrhythmias. Propafenone showed a greater rapidity of action.

[Significance of QT interval as a premonitory sign of severe ventricular arrhythmia in the early phase of myocardial infarct]

In order to evaluate the relationship between the length of the corrected QT interval (QTc), calculated according to Bazett's formula, and the incidence of ventricular fibrillation (V.F.) in the early phase of acute myocardial infarction (A.M.I.), the QTc interval was measured in 494 patients (mean age 66.42 +/- 11 years; 357 males and 137 females) assisted by the Mobile Coronary Care Unit of Florence. A.M.I. was anterior in 269 patients, inferior in 177 and non-Q in 34. The QTc interval measured on E.C.G. was recorded within the first hour after the onset of pain in 203 patients and between the first and sixth hour in 291 patients. The QTc interval was also measured in a control group consisting of 96 non A.M.I. patients with no history of coronary artery disease. 43 patients with A.M.I. (8.6%) developed V.F. in the first 24 hours. It was observed that: 1) The QTc interval of patients with A.M.I. was longer than that in patients without A.M.I. (432 +/- 34.18 msec. versus 425.37 +/- 25, p less than 0.02). 2) The QTc interval of patients with A.M.I. who developed V.F. was the same as that of patients with A.M.I. but without V.F., (432.6 +/- 34.18 msec. versus 438.11 +/- 34.13, N.S.). 3) 60.46% of patients with V.F. had a value of QTc less than 440 msec.; the incidence of QTc greater than 440 msec. showed no difference in the groups with or without V.F. (41.86% versus 41.11%). 4) The QTc interval length was greater in anterior than in inferior A.M.I. (435.12 +/- 30.81 msec. versus 429.05 +/- 34.5, p less than 0.02).(ABSTRACT TRUNCATED AT 250 WORDS)