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Biomedical subjects

I Helmy

Publications and source records attributed to I Helmy.

16 recordsLinked to original sources
PubMed1994

Use-dependent properties of flecainide acetate in accessory atrioventricular pathways.

Flecainide acetate has been shown to have use-dependent properties. The use-dependent properties of flecainide were evaluated in 20 patients (13 men and 7 women, mean age 32 +/- 11 years) with accessory atrioventricular connections. Twenty to 30 stimulus drive trains were introduced in either the atrium or ventricle at progressively faster rates. The range of cycle lengths over which anterograde and retrograde conduction block occurred in the accessory pathway was assessed in the drug-free state and after oral loading with flecainide acetate. The block cycle length index was defined as the shortest cycle length during which 1:1 conduction was maintained in the accessory pathway minus the longest cycle length during which block in the accessory pathway occurred on the second paced beat. In the drug-free state, the (mean +/- SD) anterograde and retrograde block cycle length indexes were 20 +/- 12 and 20 +/- 9 ms, respectively. After flecainide therapy, the anterograde and retrograde block cycle length indexes increased to 80 +/- 33 and 65 +/- 29 ms, respectively (p = 0.002 compared with the drug-free state). The block cycle length index did not correlate with serum flecainide levels, but did correlate with other electrophysiologic markers of drug effect on accessory pathway conduction. The change in the block cycle length index demonstrates that flecainide has a progressive effect on accessory pathway conduction at more rapid rates, consistent with its in vitro use-dependent properties. This index is an excellent marker of drug efficacy.

Adult↗
PubMed1994

Clinical and electrophysiologic spectrum of fascicular tachycardias.

The purpose of this report is to describe the clinical and electrophysiologic findings for patients with fascicular tachycardia (FT). Eight patients with FT, defined as tachycardia with HV interval during tachycardia less than that of HV of conducted impulses, were studied. ECG findings during FT included right bundle block and superior axis (four patients), right bundle branch block and inferior axis (one patient), and nonspecific intraventricular conduction delay (three patients). In three patients, entrainment as well as the ability to initiate and terminate the tachycardia favored a reentrant mechanism. In others, tachycardia initiation only over a critical range of paced cycle lengths and the incessant nature of the tachycardia or the presence of other atrial or ventricular foci favored a mechanism of either abnormal automaticity or triggered rhythms. Catheter ablation was successful in two of five patients in whom it was attempted. In conclusion, the ECG expression of FT is variable, depending on the site of origin of the arrhythmia in the ventricular specialized conduction system. Similarly, a variety of mechanisms and different foci may be associated with FT. Selected individuals may respond to catheter ablative therapy.

Adolescent↗
PubMed1991

Safety and efficacy of oral flecainide therapy in patients with atrioventricular re-entrant tachycardia.

OBJECTIVE: To assess the short- and long-term safety and efficacy of oral flecainide therapy in patients with symptomatic tachycardia and an extranodal accessory pathway. DESIGN: Open-label, uncontrolled trial with a mean follow-up of 24 months. SETTING: Referral-based, teaching medical center. PATIENTS: Sixty-three patients with symptomatic tachycardia and an extranodal accessory pathway. INTERVENTIONS: Patients had electrophysiologic testing before and after the initiation of oral flecainide therapy and were followed long-term for the presence of symptoms, new physical limitations, and adverse effects of therapy. MEASUREMENTS AND MAIN RESULTS: Flecainide therapy prevented or slowed (324 +/- 59 ms to 398 +/- 55 ms; P less than 0.001) inducible sustained atrioventricular reciprocating tachycardia in 44 of 63 patients (70%). Of the 44 patients discharged from the hospital, 33 (75%) have continued to receive flecainide therapy and have shown no adverse effects (mean follow-up, 24 +/- 10 months). Adverse cardiac reactions (proarrhythmia or sinus node suppression) attributable to flecainide occurred in 11 of 63 patients (17%); in 9 (82%) of these 11 patients, events were detected during either in-hospital monitoring or the electrophysiologic study done before discharge. Structural heart disease was detected by two-dimensional echocardiography in 8 of 11 patients who had adverse cardiac events and in 6 of 52 patients who did not have such events (P less than 0.001). Isoproterenol reversed the effects of flecainide therapy in 11 of 21 patients; 7 of the 11 patients had spontaneous clinical recurrences of tachycardia or palpitations during the follow-up period, but these symptoms occurred in only 1 of 10 patients who did not show isoproterenol-induced reversal (P = 0.02). CONCLUSIONS: Oral flecainide therapy was effective in 33 of 63 patients who had tachycardia and an extranodal accessory connection. Hospital monitoring during initial therapy is recommended, and flecainide should be used with caution, if at all, in patients with structural heart disease. An isoproterenol challenge appears to be helpful in predicting late recurrence of tachycardia.

Adolescent↗
PubMed1990

Electrophysiologic effects of isoproterenol in patients with atrioventricular reentrant tachycardia treated with flecainide.

UNLABELLED: The electrophysiologic effects of isoproterenol in patients treated with flecainide for atrioventricular (AV) reentrant tachycardia were studied to evaluate the mechanism of tachycardia inducibility after isoproterenol and the value of isoproterenol challenge as a predictor of spontaneous arrhythmia recurrence. Seventeen patients underwent electrophysiologic study before and after oral flecainide administration and after the addition of isoproterenol to flecainide. No patient had inducible sustained supraventricular tachycardia after flecainide alone. Two patients had inducible sustained and six had inducible nonsustained tachycardia after isoproterenol was added to flecainide. The patients were then followed up on the same flecainide dose they received at the time of the electrophysiologic study. FINDINGS: 1) Flecainide treatment prolonged HV and VA intervals, and the addition of isoproterenol did not affect these variables. 2) Isoproterenol shortened anterograde and retrograde block cycle length and the refractory period of the accessory pathway and the AV node. It also decreased the tachycardia cycle length, an effect that was due solely to shortening of AV node conduction time. 3) Flecainide treatment prevented tachycardia induction by affecting retrograde conduction over the accessory pathway. Isoproterenol allowed for tachycardia induction and for more sustained episodes of tachycardia by reversing the effect of flecainide on retrograde accessory pathway conduction. 4) Tachycardia recurred during follow-up in all three patients in whom tachycardia of greater than or equal to 10 s duration was induced after isoproterenol but in no patient who had no or shorter episodes of induced tachycardia (and who did not have a change in medical regimen). CONCLUSIONS: 1) Isoproterenol reverses flecainide-induced prolongation of block cycle length and refractory periods of the accessory pathway and AV node. 2) Isoproterenol reverses flecainide-induced prevention of tachycardia induction through reversal of the effects of flecainide on the retrograde accessory pathway. 3) The addition of isoproterenol during flecainide restudy is valuable in predicting long-term drug efficacy.

Cardiac Pacing, Artificial↗
PubMed1989

Long-term results of amiodarone therapy in patients with recurrent sustained ventricular tachycardia or ventricular fibrillation.

Four hundred sixty-two patients, all with either documented spontaneous sustained ventricular tachycardia or cardiac arrest unresponsive to other antiarrhythmic drugs (2.6/patient), were treated with amiodarone. Thirty-five patients (7.6%) failed to respond or died during the initial oral or intravenous loading phase. The remaining 427 patients were discharged on treatment with oral amiodarone and followed up for up to 98 months. Recurrence of ventricular tachycardia or sudden cardiac death at 1, 3 and 5 years by life-table analysis was 19%, 33% and 43%, respectively, for patients discharged on amiodarone therapy. The sudden cardiac death rate was 9%, 15% and 21%, respectively, at 1, 3 and 5 years. Side effects were reported by 45% of patients after 1 year, by 61% after 2 years and by 86% after 5 years. Amiodarone was discontinued because of side effects in 14%, 26% and 37% of patients after 1, 3 and 5 years, respectively. Incidence rates of recurrence of arrhythmia, sudden cardiac death and side effects were highest in the early months and then decreased. By multivariate analysis, advanced age, low ejection fraction and a history of cardiac arrest were independent risk factors for sudden cardiac death during amiodarone therapy.

Aged↗
PubMed1989

Seroprevalence of Rickettsia typhi and Rickettsia conorii infection among rodents and dogs in Egypt.

A serological survey of 1813 rodent and 549 dog sera, collected from 1979 to 1986 from animals in 16 Egyptian Governorates were tested for antibody to Rickettsia typhi and Rickettsia conorii by the indirect fluorescent antibody test. Only three of 82 (4%) sera from Rattus rattus collected near Aswan had antibody to R. conorii. The prevalence of R. typhi antibody in dog sera was only 0.4% (n = 549) while 25% (n = 547) of Rattus norvegicus and 11% (n = 1138) of R. rattus had measurable antibodies. Among the other rodents, antibody was demonstrated in only 2% (n = 45) of Arvicanthis spp., and 1% (n = 83) of Acomys spp. Collectively, rodents captured in the Nile Delta had a higher prevalence (mean 24% (n = 787] than those captured in the Nile Valley (mean 4% (n = 650]. Antibody to R. typhi was detected in rodents collected in all port cities: ismailiya, 13%; Port Said, 9%; Suez, 9%; Safaga, 16%; Quseir, 32% and Alexandria, 34%. These data showed evidence of R. typhi infection among rodents in widespread geographic localities of Egypt and suggested that infected rodents may be a source of human infections.

Animals↗
PubMed1988

Use of intravenous amiodarone for emergency treatment of life-threatening ventricular arrhythmias.

Efficacy, side effects and predictors of response for intravenous amiodarone were evaluated in 46 patients with recurrent drug-refractory sustained ventricular tachycardia or ventricular fibrillation, or both, who were treated with intravenous amiodarone. Of the 46 patients, 27 (58.5%) responded early to intravenous amiodarone and 6 (13%) showed a late response to amiodarone. The majority of patients who responded to intravenous amiodarone did so within the first 2 h of therapy, and all responded within 84 h. Patients with an ejection fraction greater than 25% were more likely to respond (p less than 0.05). Major side effects occurred in 13% of patients. The cumulative 2 year mortality rate due to arrhythmia recurrence or sudden death for responders discharged from the hospital was 23% and the cumulative overall 2 year mortality rate was 46%. In conclusion, intravenous amiodarone is rapidly effective in the majority of patients with recurrent ventricular tachycardia or ventricular fibrillation refractory to other drugs. The poor long-term outcome of patients who require this therapy, respond to it and are discharged on long-term oral amiodarone therapy warrants consideration of other long-term treatment of these patients. Use of intravenous amiodarone is an important new modality in the treatment of drug-refractory malignant ventricular arrhythmias.

Amiodarone↗
PubMed1988

Esophageal transection by the EEA stapler for bleeding esophageal varices in schistosomal hepatic fibrosis.

Thirty patients with esophageal varices due to schistosomal hepatic fibrosis underwent surgical treatment. They were divided into two groups. The elective group consisted of 20 patients who underwent splenectomy, gastroesophageal devascularization with esophageal transection using the EEA (U.S. Surgical Supply) stapler. The emergency group included ten patients, one of whom had the same procedure as those in the elective group and nine patients who had only esophageal transection with the EEA stapler. The use of the stapler in performing splenectomy and the devascularization operation did not decrease the recurrence of bleeding. Esophageal stapling in the emergency group controlled the bleeding in 90 per cent of the patients. The reappearance of esophageal varices and gastric varices in three patients in the emergency group was managed by distal splenorenal shunt operation.

Adolescent↗
PubMed1987

The distal splenorenal shunt in patients with variceal bleeding due to schistosomal hepatic fibrosis.

Twenty consecutive patients classified as Child's A and B with variceal bleeding from schistosomal hepatic fibrosis were electively managed by the distal splenorenal shunt. Patients were assessed clinically by angiography and were observed for up to 16 months. The over-all survival rate was 85 per cent with an operative mortality rate of 10 per cent. All of the patients had patent shunts as confirmed angiographically and all maintained hepatic perfusion; there was also a 40 per cent immediate reduction in the size of the spleen postoperatively as measured on the angiograms. None of the patients had encephalopathy and only two patients had postoperative ascites.

Adult↗
PubMed1985

Injection sclerotherapy for esophageal varices caused by schistosomal hepatic fibrosis.

Sixty patients with esophageal varices caused by schistosomal hepatic fibrosis were managed by injection sclerotherapy. Bleeding was controlled in 17 of 20 patients (85%) with acute bleeding from varices. The remaining 40 patients were either unfit for operation or had a recurrence of variceal bleeding after operation. In a period of follow-up that ranged from 14 to 31 months (mean 18.4 months), 11 patients (18.3%) had a recurrence of bleeding that was controlled and four patients (6.7%) had a fatal recurrence of bleeding. The overall mortality rate was 25% (15 patients), and 34 patients (56.7%) had no recurrence of bleeding.

Adolescent↗
PubMed1983

Colorectal schistosomiasis. Endoscopic polypectomy.

The role of colonoscopic polypectomy for schistosomal polyps was studied. The results showed that, in spite of the large number of polyps, a total of 404 polyps were removed from 20 patients. The procedure is feasible with minimal complications. A marked reduction of rectal bleeding occurred in half the patients, and the remaining half had minimal symptoms. Colonoscopic polypectomy gives equal results to colonic excision for schistosomal polyps.

Adolescent↗
PubMed1980

Endoscopic diagnosis of immunoproliferative small intestinal disease (IPSID).

Six patients with immunoproliferative small intestinal disease (IPSID), were examined endoscopically. The disease was found to involve the duodenum and jejunum and was characterized by the loss of the mucosal circular folds, a thickened cobblestone appearance of the mucosa and multiple sessile polyps. Ulceration of the mucosa was seen in one patient. A large ulcerated mass was seen in the third part of the duodenum in one patient.

Adult↗
PubMed1979

Colorectal schistosomiasis: clinicopathologic study and management.

Forty patients with colorectal schistosomiasis who failed to respond to medical therapy were studied. They had dysentery with bloody mucus and anemia, polyps, pericolic masses, and schistosomal ulcers. Two patients had cecal masses which appeared to be intussusception and appendicitis. Three patients had chronic intestinal obstruction. Diverting transverse colostomy, followed by other surgical procedures, is the safest method of management.

Adolescent↗
PubMed1977

Rabies in the Arab Republic of Egypt: III. Enzootic rabies in wildlife.

Five hundred and thirty-two rodents (10 species) and 112 other wild mammals (six species) were examined for rabies infections in Egypt. Rabies virus was isolated from the brains of three (1-2%) of 249 Gerbils, Gerbillus gerbillus and one (1-8%) of 56 foxes, Vulpes species. In neutralization tests these isolates were found to be identical to classical rabies virus. Significant numbers of rodent and other wild mammal species need to be examined before they may be excluded as possible reservoirs of rabies virus in Egypt. Based on initial findings it may be wise to reevaluate antirabies treatment for rodent bites occurring within the Arab Republic of Egypt.

Animals↗