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Biomedical subjects

D V Cokkinos

Publications and source records attributed to D V Cokkinos.

At least 19 recordsLinked to original sources
PubMed1992

Electrophysiological and electropharmacological studies in pre-excitation syndromes: results with propafenone therapy and isoproterenol infusion testing.

To study the electrophysiological effects of oral propafenone on accessory pathways and determine the potential for catecholamine-mediated reversal of these effects, comprehensive electrophysiology studies (EPS) were conducted in 11 patients with manifest (n = 9) or concealed (n = 2) pre-excitation syndrome. EPS were performed at baseline (in the drug-free state), after oral propafenone loading, and with isoproterenol infusion during propafenone therapy. The study group included 10 men and 1 woman with a mean age of 39 +/- 13 years, who presented with symptoms of palpitations (n = 6), presyncope (n = 3) and syncope (n = 2). The clinical arrhythmia was atrioventricular reciprocating tachycardia (n = 6), atrial flutter/fibrillation (n = 3), or both (n = 2). During the baseline EPS the accessory pathway location was identified as left (n = 6) or septal (n = 5). The mean anterograde effective refractory period was 265 +/- 42 ms, the shortest pre-excited RR interval 259 +/- 20 ms and the retrograde refractory period 258 +/- 39 ms. Orthodromic atrioventricular reciprocating tachycardia was induced in 10 patients (mean cycle length = 324 +/- 31 ms). Antidromic reciprocating tachycardia was induced in one patient (cycle length = 340 ms). In all the 11 patients EPS were repeated after 4 days of oral propafenone loading (668 +/- 226 mg daily) when drug steady state was expected to have been achieved. One additional patient had baseline EPS but developed clinical arrhythmia recurrences after propafenone loading and thus he was excluded from the study; follow-up EPS were conducted on procainamide.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenergic beta-Antagonists↗
PubMed1992

Effect of successful coronary angioplasty on the signal-averaged electrocardiogram.

The effect of successful coronary artery angioplasty on the signal-averaged electrocardiogram (SAECG) was examined in 50 patients (41 men, 9 women, aged 55 +/- 8 years) with stable (26 patients) or unstable angina (24 patients) and good overall left ventricular function (ejection fraction = 55% +/- 8%). The SAECG was recorded before and within 24-48 hours after the angioplasty and was filtered at 40-250 Hz, with 250 beats averaged. The noise level averaged 0.57 +/- 0.15 microV before and 0.56 +/- 0.17 microV after the procedure. There was no overall significant difference between pre- and postangioplasty SAECGs. Subgroup analysis showed that 14 patients had a significant increase of the root mean square voltage of the last 40 msec of the filtered QRS that was independent of noise level changes, previous myocardial infarction, stable or unstable angina status, positive or negative baseline SAECG, or vessel being dilated. Eleven patients (22%) had late potentials at baseline, of whom four (36%) lost them after angioplasty, while one patient developed them after the procedure, all due to root mean square voltage changes. Thus, successful angioplasty exerted no significant overall effect on the SAECG, suggesting that the substrate of late potentials was not grossly altered by the procedure in our patients. However, there appear to be some patients, constituting approximately one third of this study population, who derive a favorable influence on the SAECG from angioplasty, a subgroup that needs to be further defined in future studies.

Angina Pectoris↗
PubMed1990

The ST segment axis as a differential diagnostic feature between acute pericarditis and acute inferior myocardial infarction.

The ST segment electrical axis in the frontal plane was calculated in 20 patients with an acute inferior myocardial infarction (AIMI) and another 20 patients with the acute phase of pericarditis (AP). The ST segment axis of patients with AIMI ranged from 100 degrees-120 degrees (mean 114 degrees). The ST segment axis of patients with AP ranged from 30 degrees-60 degrees (mean 45 degrees). Thus, the ST segment axis can be used for the differential diagnosis in the early acute phase, especially when there are no other important distinguishing factors between these two conditions.

Acute Disease↗
PubMed1990

Exercise testing after acute myocardial infarction. How much? How soon?

Exercise testing shortly after acute myocardial infarction is considered safe and valuable for the determination of long-term prognosis. One point of discussion is whether a submaximal pre-discharge test or a maximal test at 6-8 weeks, which has a higher sensitivity for diagnosing multivessel disease should be preferred. The former is the authors' choice, since the submaximal predischarge test has excellent prognostic value for adverse effects, and because approximately 1.5% of patients who have a positive test have been noted to present with early ischemic deaths which ideally could have been prevented. In patients unable to exercise, mortality is about 19%. In these, the ejection fraction should be determined, and "stress" tests should be carried out administering dipyridamole or dobutamine intravenously and probably augmenting the diagnostic sensitivity of the test by radionuclide or echocardiographic evaluation.

Echocardiography↗
PubMed1989

The effective treatment of multifocal atrial tachycardia with amiodarone.

Multifocal atrial tachycardia (MAT) was observed in 9 patients aged 60-85 (mean 72.1 +/- 8.6) years during exacerbation of their chronic lung and/or cardiac disease. Four, in whom the rapid heart rate caused symptoms of pulmonary congestion, were treated with intravenous amiodarone (450-900 mg over 2 hours) with restoration of sinus rhythm soon after the termination of the drug infusion. In 1, with recurrence of MAT, the same intravenous dosage was repeated for 2 consecutive days, with final achievement of stable sinus rhythm. Five patients, apart from the conventional management of their underlying disease (digitalis, diuretics, aminophylline) were treated with oral amiodarone (600 mg/day). Sinus rhythm was restored in all and remained stable during their hospitalization, under alpha maintenance dosage of 200-400 mg daily. Amiodarone may be the drug of choice for the treatment of MAT, for which up to now no effective therapy has been established.

Administration, Oral↗
PubMed1989

Atrial septal defect and constrictive pericarditis. An unusual combination.

We describe a case of atrial septal defect associated with constrictive pericarditis. This combination is extremely rare and clinically misleading, since it may simulate other more common conditions. A variety of techniques, such as computerized tomography, echocardiography and cardiac catheterization were necessary for establishing the right diagnosis. Although there are suggestions of a possible association of atrial septal defect with pericardial disease, it is difficult to prove that this combination is other than coincidence.

Aged↗
PubMed1988

Q and non-Q wave myocardial infarction: current views.

The new terminology "Q and non-Q wave myocardial infarction" (MI) tends to replace the traditional terms "transmural" and "subendocardial" MI since the anatomy cannot be accurately predicted by electrocardiography. Although some subtypes of non-QMI display a favorable early or in-hospital prognosis, the long-term outlook seems less benign, particularly when early or late recurrence of MI occurs. Coronary arteriograms show an equal number of diseased vessels in both types of MI, but complete coronary artery occlusion is less frequent in non-QMI. The management of patients with non-QMI should be mainly directed to preventing extension or recurrence of MI by using either drugs such as thrombolytic agents and drugs against coronary artery spasm or invasive techniques like percutaneous transluminal coronary angioplasty.

Electrocardiography↗
PubMed1988

Arrhythmogenic right ventricular dysplasia: case report presentation and review of the literature.

A man complaining of palpitations was found to have ventricular tachycardia (VT) with LBBB configuration. From the investigations which followed, he was diagnosed as having arrhythmogenic right ventricular dysplasia (ARVD). The patient has been treated with amiodarone and propafenon for 7 months without VT recurrence. ARVD and Uhl's anomaly, which is its most extreme form, may be familial and represent an important cause of sudden death among young people: Prophylactic antiarrhythmic therapy and sometimes surgical treatment are required in case of refractory VT.

Bundle-Branch Block↗
PubMed1988

New criteria to increase the reliability of systolic time intervals in left bundle branch block and right ventricular pacing.

We measured the systolic time intervals (STI) in 14 patients (pts) with intermittent left bundle branch block (LBBB) in order to find correlations and comparisons in their values which might pertain to the individual patients, with (b) and without (a) LBBB. QS2I, PEP and the PEP/LVET ratio increased significantly (b) while the LVET I did not change. STI correlation was significant and improved further when the QS2 (b) was corrected by subtracting from it the QRS prolongation (b) in msec. All 7 pts with a PEP/LVET ratio (b) greater than 0.65 had an (a) ratio greater than 0.42 (normal limits for our laboratory), sensitivity 100%. Six of 7 patients with a PEP/LVET (b) less than 0.65 had an (a) ratio less than 0.42 (specificity 87.5%). For the individual patient with LBBB his STI can be quite accurately assessed by subtracting from his QS2 (b) the prolongation of the QRS (b) greater than 80 msec the length of the normal QRS duration. The above data were prospectively evaluated in 10 pts to whom intermittent right ventricular pacing was applied. We found that the correction of the QS2 interval for QRS prolongation permitted a very reliable calculation of the STI.

Aged↗
PubMed1988

Diastolic coronary artery narrowing due to left ventricular dilatation.

A 56 year old man with a large anterior myocardial infarction and diffuse left ventricular hypocontractility and dilatation was found to have narrowing of the distal part of the left anterior descending coronary artery in diastole. This most unusual finding was ascribed to diastolic compression of the vessel by the enlarged left ventricle. Only 3 similar cases have been found in the literature up to now.

Cardiomyopathy, Dilated↗
PubMed1987

The efficacy of propafenone on exercise-induced ventricular arrhythmias.

We studied the efficacy of propafenone in 16 patients (pts) with exercise-induced ventricular arrhythmias (VA). Propafenone was given in doses of 450 mg (13 pts) to 900 mg (3 pts) per day and was compared with placebo. An arrhythmic index was calculated by dividing the frequency and severity of VA by the duration of exercise test (in min). Propafenone reduced that VA index from 17.05 +/- 16.32 to 3.75 +/- 7.47 (P less than 0.005). In 8 pts the VA were completely abolished, and in 8/10 grade greater than or equal to 3 VA, while no significant change was seen with placebo. In 8 pts in whom exercise had been prematurely terminated because of significant VA, a longer duration was achieved with propafenone (from 4.19 +/- 2.74 to 9.39 +/- 1.63, P less than 0.02). In those with the same pre-planned duration, a smaller peak heart rate was seen with propafenone. Resting P-R was significantly prolonged.

Adult↗
PubMed1987

The influence of R-wave amplitude on the degree of ST-segment depression in exercise electrocardiography in the individual patient.

Many factors have been found to influence the magnitude of ST-segment depression in the exercise electrocardiogram. We investigated whether R-wave amplitude is a significant factor. We studied the exercise electrocardiogram of 20 patients with angiographically documented coronary artery disease, including greater than or equal to 70% stenosis of the left anterior descending artery, who had an ischemic response to exercise but no previous anterior myocardial infarction. Precordial leads V1-6 were taken into account. When all 120 leads were measured, those with ST-segment depression greater than or equal to 2.0mm at peak exercise had a mean resting R-wave amplitude of 19.03 +/- 5.81mm; those with ST-segment depression 2.0-1.0mm, R 11.42 +/- 5.99mm; and those with ST-segment depression less than 1.0mm, R 5.9 +/- 5.21mm (p less than 0.001 between groups). When the R-wave amplitude was correlated with the ST-segment depression in each precordial lead, the correlation was 1.0. In leads V1-6, when 67 tracings with ST-segment depression greater than 0.5mm were measured, the correlation was 0.537 (p less than 0.001). In each precordial lead the t values of R-wave differences correlated very strongly (r less than 0.883) with the differences in ST-segment depression. We conclude that precordial R-wave amplitude significantly influences the magnitude of ST-segment depression.

Coronary Disease↗
PubMed1987

Calcification of the tricuspid annulus. Case report and review of the relevant literature.

We present a case of tricuspid annulus calcification, documented by fluoroscopy, chest X-ray and cross sectional echocardiography. This case is interesting for two reasons: 1) Tricuspid annulus calcification is extremely rare and very few cases have been reported. 2) It is the third case described where two-dimensional echocardiography established the diagnosis of this very rare condition. Previously reported cases of tricuspid annulus calcification are reviewed.

Aged↗
PubMed1986

The QS2/QT ratio as an index of appropriate left ventricular response to autonomic and inotropic stimuli.

Dissociation between duration of electrical and mechanical systole has been seen with increase of myocardial shortening velocity or adrenergic activity. We found a decrease of the QS2/QT ratio after exercise in 10 pts with semisitting bicycle maximal exercise test and a normal radionuclide angiogram. No change was seen in 9 patients with a normal study with beta blockade, and in pts with a abnormal radionuclide test, without beta blockade (11 pts). In 19 normal active individuals, a significant QS2/QT decrease (p less than 0.001) was seen after a submaximal exercise treadmill test, which was inhibited by beta blockade. We believe that QS2/QT diminution is suggestive of an increase of the inotropic state of the left ventricle with exercise, produced through adrenergic stimulation. It is not seen either when an ischemic left ventricle cannot adequately respond to exercise or after beta blockade.

Adult↗
PubMed1985

Correlations of systolic time intervals and radionuclide angiography at rest and during exercise.

Systolic time intervals (STI) were correlated with radionuclide angiography studies (RAS) in 57 patients at rest, during maximal semisitting bicycle exercise, and at 4 minutes following the cessation of exercise. Eleven were judged as being free of coronary artery disease (group 1), while 14 had coronary artery disease without (group 2A), and 27 (group 2B) with a previous transmural myocardial infarction. For RAS, resting radionuclide ejection fraction (REF), the changes in REF and end-systolic volume, and the development of a wall motion abnormality at peak exercise were each highly correlated with the presence of coronary disease (p less than 0.001). The accuracy of STI parameters in predicting the presence of coronary disease was poor (less than 60%). Changes in end-diastolic volume (EDV) correlated significantly with PEP/LVET and LVET1 changes following exercise. Moreover, patients with an abnormal (greater than 25%) increase in EDV at peak exercise had a greater increase in LVET1 in the postexercise period (p less than 0.01). We conclude that STI is not accurate enough a predictor of coronary disease or left ventricular function to serve as a useful screening test. Changes in STI parameters appear to be more related to changes in ventricular volume than to ventricular function.

Adult↗