Search PubMed⌕ Search

Biomedical subjects

S Swiryn

Publications and source records attributed to S Swiryn.

At least 55 records · Page 3Linked to original sources
PubMed1984

Pharmacological observations in patients with nodoventricular pathways.

Three patients with accessory nodoventricular pathways and re-entry tachycardia are reported. In all three patients the accessory nodoventricular pathway formed the anterograde limb of the re-entry circuit while the His-Purkinje-atrioventricular node axis formed the retrograde limb of the tachycardia in two of the patients and a concealed accessory pathway formed the retrograde limb in the remaining patient. All three patients also manifested dual anterograde atrioventricular nodal pathways with conduction through the accessory nodoventricular pathways being associated with the atrioventricular nodal fast pathway. Type I antiarrhythmic drugs, especially disopyramide and quinidine, were effective for the treatment of the re-entry tachycardia because of their depressive action on the nodoventricular pathway. Beta blockers were also effective because of their action on the atrioventricular nodal portion of the re-entry circuit in one patient and most probably due to atypical (atrioventricular nodal like) properties of a retrogradely conducting accessory pathway in a second patient.

Adolescent↗
PubMed1984

Pulmonary toxicity of amiodarone.

Mild pleuroparenchymal fibrosis associated with amiodarone pulmonary toxicity is reported in a 63-year-old white man; partial radiographic resolution and complete symptomatic resolution with decreasing the daily dosage to 200 mg permitted continued anti arrhythmic therapy.

Amiodarone↗
PubMed1983

Equilibrium radionuclide gated angiography in patients with tricuspid regurgitation.

Equilibrium gated radionuclide angiography was performed in 2 control groups (15 patients with no organic heart disease and 24 patients with organic heart disease but without right- or left-sided valvular regurgitation) and in 9 patients with clinical tricuspid regurgitation. The regurgitant index, or ratio of left to right ventricular stroke counts, was significantly lower in patients with tricuspid regurgitation than in either control group (range and mean +/- standard error of the mean 0.4 to 1.0, 0.7 +/- 0.1 versus 1.0 to 1.5, 1.3 +/- 0.1 and 1.0 to 2.9, 1.5 +/- 0.1, respectively, p less than 0.001). Time-activity variation over the liver was used to compute a hepatic expansion fraction which was significantly higher in patients with tricuspid regurgitation than in either control group (1.4 to 11.4, 5.8 +/- 1.0% versus 0.6 to 3.4, 1.9 +/- 0.3% and 1.0 to 5.1, 2.3 +/- 0.2%, respectively, p less than 0.001). Fourier analysis of time-activity variation in each pixel was used to generate amplitude and phase images. Only pixels with values for amplitude at least 7% of the maximum in the image were retained in the final display. All patients with tricuspid regurgitation had greater than 100 pixels over the liver automatically retained by the computer. These pixels were of phase comparable to that of the right atrium and approximately 180 degrees out of phase with the right ventricle. In contrast, no patient with no organic heart disease and only 1 of 24 patients with organic heart disease had any pixels retained by the computer. In conclusion, patients with tricuspid regurgitation were characterized on equilibrium gated angiography by an abnormally low regurgitant index (7 of 9 patients) reflecting increased right ventricular stroke volume, increased hepatic expansion fraction (7 of 9 patients), and increased amplitude of count variation over the liver in phase with the right atrium (9 of 9 patients).

Adolescent↗
PubMed1983

Chronic recurrent right ventricular tachycardia in patients without ischemic heart disease: clinical, hemodynamic, and angiographic findings.

Surgical cure of right ventricular tachycardia (RVT) has been recently described in patients with "arrhythmogenic right ventricular dysplasia," a disease characterized by abnormal electrical activation of the right ventricle and localized or generalized angiographic right ventricular (RV) wall motion abnormalities (WMA). In search of a selective RV cardiomyopathy complicated by chronic recurrent RVT, 38 consecutive patients (mean age 30.5 +/- 12 years) with RVT and no ischemic heart disease were studied clinically, noninvasively, and by cardiac catheterization including left and right ventriculography. RV volumes were as follow: end-systolic volume ranged from 23 to 103 (mean +/- SD, 45.8 +/- 20) cc/m2 and was abnormal in 14 patients (37%); end-diastolic volume ranged from 57 to 138 (90.5 +/- 26) cc/m2 and was abnormal in 15 patients (39%); ejection fraction (EF) ranged from 0.18 to 0.64 and was decreased in five patients (13%). Seventeen patients (45%) had abnormal RV volume, EF, and/or pressures (RVD), five (13%) of whom had abnormal LV volume, EF, and/or pressures (LVD), and 12 (32%) patients with RVD had no LVD. Twenty-one patients (55%) had no RVD, two of whom had LVD. Only two of the 17 patients had RV regional WMA, one with and one without LVD. Most patients with LVD five of seven (71%) also had RVD while 12 of 31 patients (39%) with no LVD had RVD. In conclusion, less than one half of patients with RVT had selective RV cardiomyopathy and more than one half of patients with RVT had normal RV hemodynamics and angiography.

Adolescent↗
PubMed1983

Angiographic correlates of recurrent sustained ventricular tachycardia in chronic ischemic heart disease.

We report the angiographic studies of 53 consecutive patients with angiographic coronary artery disease (CAD) and recurrent sustained ventricular tachycardia occurring at least 6 weeks remote from an acute myocardial infarction. Triple-vessel disease was present in 25 patients (47%), double-vessel disease in 19 patients (36%), and single-vessel disease in nine patients (17%). All patients with single-vessel disease had left anterior descending coronary artery obstruction. Patients under 50 years old had significantly fewer diseased vessels than those over 50 years old (1.4 vs 2.4 vessels diseased; p less than 0.025). Left ventricular ejection fraction ranged from 0.15 to 0.61 (mean 0.34 +/- 0.11) and was 0.25 or less in 14 patients (26%). All patients had regional wall motion abnormalities. There was akinesia and/or dyskinesia in 49 patients (92%). Akinesia or dyskinesia was inferior in 17 patients (32%), anteroapical in 14 patients (26%), inferoapical in 10 patients (19%), and anteroapicoinferior in 6 patients (11%). Involvement of the septum was noted in 19 patients (36%) and of basal segments in 26 patients (49%). An average of 2.7 (out of seven) segments per patient were dyskinetic or akinetic. Thus multivessel disease, markedly reduced ejection fraction, and severe and extensive regional wall motion abnormalities are generally present. These findings have pathophysiologic as well as clinical and therapeutic implications. The nautral history of these patients as well as the results of therapy should be related to the underlying coronary anatomy and left ventricular function.

Adult↗
PubMed1983

Electrophysiologic testing of bretylium tosylate in sustained ventricular tachycardia.

We used programmed ventricular stimulation to test intravenous bretylium tosylate in 10 consecutive patients with inducible sustained ventricular tachycardia (usually refractory to type I antiarrhythmic agents). These 10 patients had previously documented sustained ventricular tachycardia and/or ventricular fibrillation complicating stable heart disease. Following control inductions of sustained ventricular tachycardia, bretylium 10 mg/kg was infused over 30 minutes. Thirty minutes after this infusion, sustained ventricular tachycardia could be induced in 9 of the 10 patients (one of these nine patients also had bretylium-potentiated spontaneous ventricular tachycardia). Tachycardia induced in the nine patients after bretylium was similar to control tachycardia with respect to morphology and cycle length (333 +/- 16 msec after bretylium versus 330 +/- 16 msec during control). However, five of the nine patients tolerated induced tachycardia less well after bretylium (exacerbated hypotension). In one patient, ventricular tachycardia could not be induced after intravenous bretylium.

Administration, Oral↗
PubMed1983

Concordance and discordance of drug responses in atrioventricular reentrant tachycardia.

Whether the results of some drug studies could be used to predict the results of other drug studies was examined during serial electrophysiologic drug testing in patients with sustained atrioventricular reentrant tachycardia. The drugs studied were intravenous propranolol, 0.1 mg/kg; intravenous ouabain, 0.01 mg/kg; the combination of propranolol plus ouabain; intravenous procainamide, 0.75 to 1.5 g; oral quinidine, 1.2 to 2.4 g/day; and oral disopyramide, 0.8 to 1.6 g/day. Response was inability to induce sustained tachycardia after administration of a drug. Responses due to increased anterograde limb refractoriness. Six of 10 patients with response to propranolol plus ouabain versus 0 of 9 patients without response to this combination had response to propranolol alone (p less than 0.01). Seven of 14 patients with response to the combination versus 0 of 9 patients without response to the combination had response to ouabain alone (p less than 0.05). Responses due to increased retrograde limb refractoriness. Eight of 9 patients with response to procainamide versus 2 of 17 patients without response to this drug had response to quinidine (p less than 0.01). There was not a significant relation between response to procainamide and response to disopyramide, or between response to quinidine and response to disopyramide. Anterograde limb versus retrograde limb. There was not a significant relation between response to propranolol plus ouabain and response to any class I drug. In conclusion, there are relations between drug responses during electrophysiologic studies in patients with atrioventricular reentrant tachycardia. Thus, it should be possible to simplify these studies.

Adolescent↗
PubMed1983

Familial inducible torsade de pointes with normal QT interval.

A familial presentation of torsade de pointes is described. The propositus had recurrent syncope, documented torsade de pointes, a normal Q-T, and close coupled premature ventricular beats initiating the paroxysmal arrhythmia. The mother had sporadic syncope without documented torsade de pointes, a normal Q-T, and closely coupled premature ventricular beats. Electrophysiological studies demonstrated reproducible inducible torsade de pointes tachycardia in both patients. Serial drug testing in both revealed suppression of induced torsade de pointes with oral propranolol. Chronic oral propranolol resulted in clinical cure in both patients.

Adult↗
PubMed1983

Detection and quantification of regional wall motion abnormalities using phase analysis of equilibrium gated cardiac studies.

Phase images obtained from equilibrium gated cardiac studies were evaluated for qualitative and quantitative information and correlated with contrast angiography in 33 patients. The left ventricular region of interest was obtained by a semiautomatic procedure which avoided underestimation of size but also eliminated extraventricular pixels. Phase images and phase distribution histograms were arranged in three standard displays which included the whole heart, isolated left ventricle, isolated abnormal areas, and quantification of maximum phase shift in the whole free border and in the inferolateral and posterolateral segments. Only the free left ventricular border was evaluated. According to contrast angiography results, four categories were obtained: normal, hypokinetic, akinetic, and dyskinetic. The best correlation with contrast angiography was found with the results obtained by dividing the left ventricular free border in two segments (r = 0.91). Scheffe's test for multiple comparisons showed significant differences between each of the four categories. Expressed in phase shifts from the histogram mode, the lower limits for the three abnormal categories were established at 30 degrees, 78 degrees, and 156 degrees respectively for hypokinetic, akinetic, and dyskinetic segments. For distinguishing normal from abnormal segments, sensitivity = 83%, specificity = 94%, and accuracy = 89%. The main reasons for discrepant results appeared to be small hypokinetic areas in an otherwise normal ventricle, very large area of hypokinesia, segments adjacent to an area of marked abnormality, and ventricles with asynchrony (wave-like motion). The method described provides an image which characterizes myocardial synchrony, generates clear boundaries for abnormal areas, and lends itself to quantification.

Adolescent↗
PubMed1983

Long-term follow-up of patients receiving aprindine. Safety and efficacy.

Aprindine hydrochloride is an antiarrhythmic agent presently undergoing clinical trials in the United States. Because of the narrow therapeutic-toxic ratio observed for aprindine, the long-term follow-up of these patients is important in determining the potential clinical effectiveness of this drug. In this report we examine our experience with 30 patients with drug-resistant arrhythmias who were discharged receiving aprindine and who were followed up for a mean period of 25 months.

Adolescent↗
PubMed1982

The conduction system in Pompe's disease.

We report our findings in the microscopic examination of the conduction system in four infants with glycogen storage disease, one of whom had adequate electrophysiologic studies. The electrophysiologic studies in the latter case showed P-A and A-H intervals at the lower limits of normal, but the H-V interval was just above the normal mean. This suggests that the rapid conduction was not localized in the anatomic counterpart of the H-V interval. The short P-R interval in the ECG may be related to the enlargement of cells, which may in turn be related to increased glycogen content. The relationship of glycogen per se to the speed of conduction is unknown. We found that the summit of the ventricular septum bulged, probably because of the generally increased cell size, and that the topography of the atrioventricular conducting system was different from normal. This is possibly related both to an increase in the cell sizes of the specialized conducting tissue itself and to deforming effects of this bulging summit of the ventricular septum. New microscopic details of the components of the conducting system are described in these cases.

Cardiomegaly↗
PubMed1982

M-mode echocardiography in left bundle branch block: significance of frontal plane QRS axis.

M-mode echocardiograms were obtained in 48 patients with complete left bundle branch block (LBBB). Of these 48 patients, 28 had LBBB with normal frontal plane QRS axis (-20 degrees to +90 degrees, mean +/- SD 18 degrees +/- 34 degrees), and 20 had LBBB with a left axis deviation (LAD) (-30 degrees to -60 degrees, mean +/- SD -48 degrees +/- 11 degrees). In the group with LBBB and normal axis, 25 patients had typical early mean +/- SD -48 degrees +/- 11 degrees). In the group with LBBB and normal axis, 25 patients had typical early systolic posterior septal motion characteristic of LBBB. Septal motion following early posterior septal motion (through the ejection period) was posterior in 24 patients (86%), anterior (paradoxical) in 2 (7%), and flat in 2 (7%). In the group with LBBB and LAD, 16 patients had the typical early systolic posterior septal motion; subsequent septal motion was posterior in 3 (15%), anterior (paradoxical) in 13 (65%), and flat in 4 (20%). Patients with LBBB and normal axis had a higher frequency of posterior septal motion, and patients with LAD had a higher frequency of anterior septal motion (p less than 0.001). The correlation of abnormal axis and paradoxical septal motion may be explained by the activation pattern producing LAD or by a septal disease process producing both abnormalities of axis and abnormal septal motion.

Adolescent↗