Hanjoerg Just

Coronary vasomotion in response to sympathetic stimulation in humans: Importance of the functional integrity of the endothelium

The coronary vasomotor response to the cold pressor test was studied with use of quantitative coronary angiography in 32 patients without evidence of coronary artery disease and 55 patients with such disease; in a subset of 22 patients (9 with normal coronary arteries and 13 with coronary artery disease), the effects of the cold pressor test were compared with the effects of the endothelium-dependent vasodilator acetylcholine with simultaneous intracoronary Doppler flow velocity measurements to assess the influence of endothelial dysfunction. The cold pressor test induced vasodilation of 8.9 +/- 5.7% in all 77 analyzed vessel segments of the group with normal arteries (p less than 0.01). In contrast, in patients with coronary artery disease, the 52 analyzed stenotic segments were constricted by -12.1 +/- 9.5% (p less than 0.01), the 57 analyzed vessel segments with luminal irregularities were constricted by -8.9 +/- 5.2% (p less 0.01) and 40 (85%) of 47 angiographically normal segments also were constricted by -7.0 +/- 4.9% (p less than 0.05). Preserved vasodilating capability was demonstrated by intracoronary nitroglycerin in all analyzed segments. In nine patients with normal coronary arteries, the analyzed vessel segments were dilated in response to both the cold pressor test and intracoronary acetylcholine by 10.9 +/- 5.4% and 13.4 +/- 4.7%, respectively. In contrast, in all 13 patients with coronary artery disease, vasoconstriction of identical vessel segments by -9.1 +/- 3.7% and -23 +/- 10.4%, respectively, was observed after both the cold pressor test and intracoronary acetylcholine. Intracoronary propranolol did not significantly affect either the vasodilative response in 11 normal coronary arteries (11.3 +/- 4.4% before and 8.6 +/- 4.3% after beta-blockade) or the vasoconstrictor response in 8 atherosclerotic coronary arteries (-11.4 +/- 4.6% before and -14.6 +/- 5.3% after beta-blockade). The dilation of normal and the constriction of atherosclerotic coronary arteries with cold pressor testing exactly mirror the response to the endothelium-dependent dilator acetylcholine. Endothelial dysfunction in coronary atherosclerosis resulted in a loss of normal dilator function and permitted vasoconstrictor responses to sympathetic stimulation. Thus, coronary vasomotion of large epicardial arteries in response to sympathetic stimulation by the cold pressor test in humans is intimately related to the integrity of endothelial function.

Mode of death in idiopathic dilated cardiomyopathy: A multivariate analysis of prognostic determinants

A total of 110 patients with idiopathic dilated cardiomyopathy were followed prospectively for 53 +/- 8 (range 41 to 69) months to determine prognostic factors identifying patients at risk for sudden death or death from congestive heart failure. During the follow-up period 39 patients died, 14 of congestive heart failure and 25 suddenly. The incidence of cardiac death after 1 year was 18%, after 2 years 35%, and after 4 years 39%. Multivariate logistic regression analysis identified four independent prognostic factors: left ventricular ejection fraction, cardiac index, number of ventricular pairs/24 hours, and atrial rhythm (sinus rhythm or atrial fibrillation). With the final model of logistic regression 77 of 88 patients (88%) could be classified correctly as being at risk for death from chronic heart failure or sudden cardiac death. Patients who were likely to die of congestive heart failure were characterized by a markedly impaired left ventricular function (measured in terms of left ventricular ejection fraction, cardiac index, or both) and a low number of pairs/24 hours. The association between frequent complex ventricular arrhythmias and depressed left ventricular function identifies patients who are at risk for sudden death. The presence of atrial fibrillation significantly increases the risk of sudden death and death from congestive heart failure.

Determinants of prognosis in idiopathic dilated cardiomyopathy as determined by programmed electrical stimulation.

The incidence and prognostic significance of electrically induced ventricular arrhythmias were prospectively assessed in 42 patients with idiopathic dilated cardiomyopathy. All patients underwent 24-hour, long-term electrocardiographic (Holter) monitoring and 30 were analyzed by a signal-averaging vectorcardiographic procedure at entry into the study. Their response to programmed electrical stimulation during basic right ventricular pacing was investigated using 1 and 2 ventricular extrastimuli. A monomorphic tachycardia was not induced in any patient. In 36 patients (86%) polymorphic ventricular arrhythmias were initiated. Three or more induced consecutive ventricular premature complexes occurred in 9 patients (21%), nonsustained polymorphic ventricular tachycardia in 2 (4.8%) and ventricular fibrillation in 1 patient (2.4%). There was no association between electrically induced polymorphic ventricular arrhythmias and the degree of impairment of left ventricular function. Furthermore, the incidence of induced ventricular arrhythmias was not related to the Lown grade or to the total number of ventricular premature complexes during Holter monitoring. A late potential was detected by the averaged vectorcardiogram in only 1 of the 30 patients. During follow-up (mean 16 +/- 7 months) 7 patients died, 5 from chronic congestive heart failure and 2 from sudden cardiac death. No patient had an electrically induced arrhythmia of 3 or more ventricular premature complexes.(ABSTRACT TRUNCATED AT 250 WORDS)

Risk of transesophageal echocardiography in awake patients with cardiac diseases

Abstract Recent studies described the diagnostic value of transesophageal echocardiography in patients with different diseases of the heart and the thoracic aorta.1–8 However, the risk and potential complications of the transesophageal approach are still under discussion. Schlueter et al6 reported no major side effects during the transesophageal approach in 300 consecutive patients. In accordance with these results, Engberding et al7 also observed no complications using the transesophageal technique in patients with aortic dissection or aortic aneurysm. More recently and in a similar patient population, Erbel et al8 described a 1% incidence of side effects (namely, 1 patient with an attack of asthma and another who experienced a transient atrioventricular heart block). In a prospective study in 54 consecutive patients with different heart diseases undergoing transesophageal echocardiography, we evaluated the presence and severity of “side effects” such as cardiac arrhythmias, marked changes in blood pressure or heart rate and evidence of myocardial ischemia during the diagnostic procedure.

Determination of aortic valve orifice area in aortic valve stenosis by two-dimensional transesophageal echocardiography

Two-dimensional transesophageal echocardiography was used to measure aortic valve orifice area in 24 patients with aortic valve stenosis (AS) and 15 patients without aortic valve disease. Using transesophageal echocardiography, orifice area could be measured in 20 of 24 patients with AS. With transthoracic echocardiography, orifice area could be determined in only 2 of 24 patients. In patients with AS, orifice area determined by transesophageal echocardiography was 0.75 +/- 0.34 cm2 and that calculated with Gorlins formula was 0.75 +/- 0.32 cm2. In normal aortic valves, orifice area was 3.9 +/- 1.2 cm2 by transesophageal echocardiography. A good correlation was demonstrated between aortic valve orifice area determined using transesophageal echocardiography and calculated orifice area using Gorlins formula in patients with AS: r = 0.92, standard error of estimate = 0.14 cm2. The absolute difference between orifice area measured with both methods ranged from 0.0 to 0.4 cm2 (mean 0.09 +/- 0.1). In 4 patients orifice area could not be determined with transesophageal echocardiography. The orifice could not be identified in 2 patients because an appropriate cross-sectional view of the aortic valve could not be achieved and in 2 patients with pinhole stenosis (aortic valve orifice area 0.3 cm2). These data show that aortic valve orifice area can be measured reliably using 2-dimensional transesophageal echocardiography.

Prediction of efficacy and tolerance of oral mexiletine by intravenous lidocaine application

In a controlled crossover trial, 15 patients with frequent ventricular arrhythmias were treated with lidocaine to predict efficacy and safety of oral mexiletine. After an initial control period, patients received intravenous lidocaine (bolus infusion of 200 mg/20 min followed by 3.6 gm/24 hr and for 7 days oral mexiletine (200 mg four times a day). Efficacy was controlled by 24‐hour Holter monitoring (responders = suppression of single premature ventricular beats [PVB] >84% and of complex PVB >90%). After lidocaine, 10 of 15 patients (67%) were responders (mean PVB reduction: 97%). After mexiletine, five of 15 patients (33%) were responders (mean PVB reduction: 81%); efficacy was closely related to the plasma concentration. When efficacy of both agents was compared, lidocaine infusion had a positive predictive value of only 50%; however, the negative predictive value was 100%. Thus in nonresponders to lidocaine, mexiletine is very likely to fail in the suppression of ventricular ectopy.

Quantitative assessment of temporal and spatial ventricular wall motion in normal and infarcted human left ventricles

A new integrated method for quantitating temporal and spatial systolic wall motion heterogeneity was developed and applied in 15 normal subjects and 26 patients with previous myocardial infarction (MI). After frame by frame digitizing, right anterior oblique left cineventriculograms (LV) were analyzed with 90 spaced radii. For each radius shortening fractions at sequential systolic time points relative to end diastole were correlated with corresponding normalized time points using linear regression method, yielding the radial correlation coefficient (r) and the radial regression slope (b) for temporal and spatial information. High radial r values with small standard deviations were observed in normal LV (0.972 +/- 0.016) and in non-MI regions (0.964 +/- 0.018), indicating temporally homogeneous radial shortening. A significant temporal heterogeneity in wall motion was demonstrated in MI regions (0.480 +/- 0.304) (p less than 0.001). In comparison with normal b values (0.449 +/- 0.106), there were decreased b values in MI regions (0.203 +/- 0.211) (p less than 0.001) and increased b values in non-MI regions (0.695 +/- 0.213) (p less than 0.001), suggesting hypokinetic and compensative hyperkinetic contraction in corresponding regions. Thus, temporal and spatial wall motion throughout systole could be assessed quantitatively by the present computer-assisted method with two simple integrated parameters.

Concentrations of mezlocillin in the serum, heart valves, muscle and subcutaneous tissue of patients undergoing open-heart surgery

Summary4 g mezlocillin as a five-minute intravenous bolus were given preoperatively to 31 adult patients undergoing open-heart surgery. Mezlocillin serum levels declined from 42.8 mg/l at 1–2 h after injection to < 1 mg/l at 6–8 h after application. Concentrations in muscle and subcutaneous tissue varied between 18 µg/g and < 1 µg/g. Mezlocillin levels in heart valves were higher than those in muscle and subcutaneous tissue, thus suggesting rapid diffusion of mezlocillin.ZusammenfassungPräoperativ erhielten 31 erwachsene Patienten innerhalb einer fünfminütigen intravenösen Gabe 4 g Mezlocillin vor einer Operation am offenen Herzen. Die Serumspiegel von Mezlocillin sanken von 42,8 mg/l 1–2 Stunden nach Gabe auf < 1 mg/l 6–8 Stunden nach Injektion. Mezlocillinkonzentrationen im Muskel und subkutanen Geweben zeigten eine Schwankung zwischen 18 µg/g und < 1 µg/g. Die Mezlocillin-Spiegel waren in den Herzklappen höher als jene im Muskel und subkutanen Gewebe. Dieses Ergebnis läßt auf eine schnelle Diffusion von Mezlocillin schließen, sogar bei vernarbten Herzklappen.