John K. Vyden

Evaluation of a QRS scoring system in acute myocardial infarction: Relation to infarct size, early stage left ventricular ejection fraction, and exercise performance

Abstract Recent studies suggest that the QRS scoring system (QRSs) using observations of Q- and R-wave duration and R Q and R S amplitude ratios in the standard electrocardiogram (ECG) is useful in estimating left ventricular function after acute myocardial infarction (AMI). The correlation of QRSs with infarct size determined by serum creatine kinase MB changes and early stage left ventricular ejection fraction (LVEF) determined by multiple gated equilibrium cardiac blood pool scintigraphy was studied in 32 patients with AMI using ECGs taken 3 and 7 days after onset. The relation of QRSs to exercise performance was also examined in 45 other patients who underwent heart rate limited low level exercise test (LLET) soon after AMI (12.3 ± 5.6 days, mean ± standard deviation). The QRSs of 7 days after onset significantly correlated with both infarct size and LVEF; infarct size (CK·g·Eq) = 5.24 QRSs + 8.50 (r = 0.72, p Patients with exercise tolerance of 12 minutes (9.0 ± 3.3 versus 4.5 ± 2.4 and 3.6 ± 2.2, p 5 minutes, whereas all patients who could not exercise for > 5 minutes (10 of 45 patients) had QRSs > 5. The relation between QRSs and the reasons for termination of LLET showed that patients with fatigue or dyspnea, or both, had significantly higher QRSs (8.7 ± 4.6) than those in target heart rate (5.4 ± 2.2, p These data suggest that QRSs will be clinically useful not only as a variable correlating with infarct size and LVEF but also as an aid in early identification of exercise performance soon after AMI.

Cardiovascular effects of ajmaline

Ajmaline, a rauwolfia derivative, has been found to possess potent antiarrhythmic effects. The present study has been designed to define the cardiovascular effects of this drug. Hemodynamic studies performed in anesthetized and conscious dogs demonstrated no significant changes in measured hemodynamic parameters at doses equal to or less than 2 mg. per kilogram. Studies in isolated papillary muscle demonstrated no negative inotropic effects until concentrations of 1 X 10(-4). Disparate results were obtained with regard to heart rate reflecting the state of autonomic tone. Electrophysiologic studies in both anesthetized and conscious dogs demonstrated a significant depression of intraventricular conduction with no significant effect on AV nodal conduction; ventricular automaticity was not affected. Ajmaline did not alter digitalis-induced AV nodal conduction prolongation. However, ajmaline dramatically altered or abolished ventricular arrhythmias secondary to acute ischemia. In conclusion, these studies demonstrate that ajmaline specifically depresses intraventricular conduction, suggesting that this drug would be particularly effective in the treatment of re-entrant ventricular arrhythmias.

Peripheral hemodynamics in patients with Fabry's disease

Altered vasomotor activity has been reported as a clinically prominent feature of Fabrys disease (angiokeratoma corporis diffusum universale). While symptomatic cardiovascular involvement occurs eventually in most patients with this disorder, little is known concerning the effect of Fabrys disease on peripheral hemodynamics. Peripheral hemodynamics in the extremities and digits were studied in eight patients with Fabrys disease by means of segmental and venous occlusion pneumoplethysmography and thermal probes, and the results obtained were compared with those of 10 normal subjects. Forearm vascular resistance in Fabrys disease patients was significantly higher (p less than 0.01) than that in normal subjects. Forearm venous capacitance in Fabrys disease was significantly lower (p less than 0.01). Segmental pulse volume amplitudes showed no significant difference in any segments (upper arm, wrist, thigh, above and below knee, and the calf) between the two groups. Finger and toe blood flow, finger and toe pulse volume, and temperature in the resting state were all significantly less (p less than 0.01, p less than 0.05: p less than 0.01, p less than 0.01: p less than 0.05, p less than 0.05, respectively) than those in normal subjects. Finger and toe blood flow and pulse volume after vasodilation procedures were significantly less (p less than 0.05, p less than 0.01: p less than 0.05, p less than 0.01, respectively) than those in normal subjects despite equal elevation of digital temperature obtained after vasodilation in both groups. These findings indicate the presence of vasoconstrictive process in both resistance vessels and capacitances vessels in cutaneous and skeletal muscular beds. A limited response in the cutaneous circulation to vasodilation procedures also was seen. These data suggest the possibility that latent enhanced sympathoadrenal discharge as well as the accumulation of glycolipid in the autonomic nervous system and vessel walls plays an important role in the disturbed pathophysiology of this disorder.

Hemodynamic effects of 3-hydroxytyramine (dopamine) in experimentally induced shock.

Abstract 3-Hydroxytyramine (dopamine) appears to be an effective drug for the treatment of cardiogenic, traumatic and hemorrhagic shock states because it restores systemic pressure while it increases the blood flow to the kidney, gastrointestinal tract and coronary circulations. Concomitant use of alpha and beta adrenergic receptor blocking agents suggests that the vasodilating action of 3-hydroxytyramine is due to stimulation of beta adrenergic receptors and its pressor effect to both slight alpha adrenergic receptor stimulation and beta inotropic action.

The Effects of Transfemoral Catheterization on Blood Flow in the Extremities

The peripheral hemodynamics of 20 patients were studied 24 hours before and 24 hours following completion of Seldinger transfemoral cardiac catheterization. All patients were catheterized in the right femoral artery and vein, while in 13 an arterial needle was placed in the left femoral artery.In the catheterized leg, mean calf blood flow and venous capacitance fell while mean calf vascular resistance was increased. The placement of an indwelling arterial needle caused mean calf blood flow to fall with an increase in calf vascular resistance. Venous capacitance was unchanged. The above changes while present 24 hours after catheterization had returned to normal one week later. While no symptoms or signs of limb ischemia occurred, oscillometry showed deterioration in the lower limb pulsation amplitudes in 13 of the 20 patients. No significant changes in peripheral hemodynamics were seen in the limbs, the arteries of which had not been catheterized.Thus, although all patients were symptomless and free of signs suggestive of ischemia clinically, arterial and venous catheterization and/or the placement of an arterial needle causes significant changes which last at least 24 hours distal to the invasion of the vessels.

Observations on the relationship between digital heat loss and systemic hemodynamics in patients with heart disease

A concomitant study of finger heat discharge and systemic hemodynamics was undertaken in a series of 19 patients (mean age 54 years) suffering from various forms of heart disease. Finger heat discharge, as measured by calorimetry, was found to correlate significantly with mean circulation time (-0.760), cardiac index (+0.649), systemic vascular resistance (-0.615), stroke work index (+0.649), mean pulmonary artery pressure (-0.596), mean pulmonary capillary wedge pressure (-0.554), stroke index (+0.541), appearance time (-0.502) and mean right atrial pressure (-0.453). There was no significant correlation between finger heat discharge and mean arterial blood pressure, LV dp/dtmax, and heart rate. An effect of heart failure on finger heat discharge was found. When evidence of forward failure and also possibly backward failure was found, mean finger heat discharge was significantly diminished. When both forward and backward failure were present together, mean finger heat discharge fell still further.

Gastrointestinal Vascular Syndromes

Simultaneous measurement of blood flow in a number of regional circulations has shown that infarction of the gastrointestinal tract may occur not only as the result of local occlusion but also as the remote consequence of a cardiac crisis. Conversely, cardiac output and coronary perfusion may be reduced by ischemic events in the splanchnic bed. The clinical implications of these findings are illustrated.

Unloading Effects of Molsidomine on Peripheral Circulation and Cardiac Hemodynamics in Patients with Acute Myocardial Infarction

The unloading mechanisms and site of peripheral action of the new antian ginal drug molsidomine was compared with isosorbide dinitrate (ISDN) in 14 patients with acute myocardial infarction using a Swan-Ganz catheter and venous occlusion plethysmography. Sublingual molsidomine (2-4 mg) in creased calf venous capacitance (CVC) (0.42 ± 0.18 to 0.64 ± 0.09 ml/100 ml, p<0.05) from 30 to 240 minutes, while simultaneously lowering of PCWP (25.9 ± 4.9 to 15.8 ± 7.3 mmHg, p<0.05) and CVP (9.3 ± 3.7 to 5.8 ± 3.5 cmH2O, p<0.05). Calf blood flow (CBF), calf vascular resistance (CVR), CI, TSPR and SWI were not affected significantly. Molsidomine reduced preload more than 240 minutes after its administration. Sublingual ISDN increased CBF into the initial 15 minutes (1.19 ± 0.49 to 1.83 ± 0.98 ml/100ml/min, p<0.05) and CVC from 5 to 60 minutes (0.42 ± 0.19 to 0.68 ± 0.24 ml/100ml p<0.01) while simultaneously lowering PCWP (24.3 ± 2.2 to 14.6 ± 4.5 mmHg, p<0.01) and CVP (9.0 ± 2.8 to 5.5 ± 3.5 cmH2O, p<0.05). Neither drug affected cardiac index, blood pressure or systemic vascular resistance. These data suggest that molsidomine significantly lowered elevated preload (PCWP/CVP) by dilating venous capacitance vessels. Its length of action was 240 minutes compared with 60 minutes obtained with ISDN, which suggests this new agent may be of marked benefit in the AMI patients suffering from backward failure uncompli cated by forward failure in whom continued preload reduction is necessary. (Results are expressed as the mean ± standard deviation).

Double-Blind Study of Papaverine Hydrochloride on the Efficacy in the Treatment of Intermittent Claudication

A double-blind, placebo-controlled, parallel groups study design was utilized to evaluate the efficacy and the safety of papaverine HCL (PA, 300- 1,500 mg/day) in the treatment of intermittent claudication. The study was in two phases: Phase I-6 weeks duration with treadmill claudication tests and doppler ankle/brachial pressure studies every 2 weeks to establish disease stability; Phase II-12 weeks double-blind evaluation of PA versus placebo (PL) with treadmill claudication tests and doppler ankle/brachial pressure studies every 4 weeks. Intermittent claudication was documented by symptoms, his tory and objective evidence of decreased blood supply to the lower ex tremities : decreased resting and post-exercise ankle/brachial pressure indices (A/B Pr), diminished segmental pulse-volumes and physical findings. Data were collected to determine the distance to initial pain (IP), rapidly increasing pain (RIP) and absolute claudication (AC) during treadmill tests and also the changes in resting and post-exercise A/B Pr. In 20 patients who completed this study, the distance to RIP was increased 43% by PA and decreased 2% by PL (p=0.012). PA increased the distance to AC by 29%, but was decreased by 1% in PL (p=0.039). The A/B Pr studies showed significant less decrease in 1 minute and 2.5 minutes post exercise A/B Pr at 12 weeks in PA patients as compared to those in PL patients.

Lack of effect of cyclandelate in peripheral arterial disease.

While cyclandelate is widely used in the therapy of peripheral arterial disease, objective evidence of its efficacy remains controversial. For this reason, 12 patients with intermittent claudication (average age of 66.8 years) received both cyclandelate 400 mg qid and placebo in a double-blind crossover trial lasting two months. During the cyclandelate and placebo periods, the following peripheral hemodynamic measurements were obtained using a plethysmograph and treadmill claudication testing: mean calf blood flow, vascular resistance and venous capacitance; finger and toe blood flow, pulsation amplitude and tem perature before and after vasodilating maneuvers; arm and leg arterial pulsa tion amplitudes, one and ten minute calf reactive hyperemia reaction; 30 pound/30 second calf active hyperemia reactions and times of onset of claudi cation as measured on a treadmill. No major significant difference could be demonstrated between placebo and cyclandelate on any subjective symptom or any objective measurement. It is concluded that cyclandelate 400 mg qid for 4 weeks was of little objective value in treating this group of 12 patients with peripheral arterial disease and suffering from intermittent claudication.