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The value of long-term electrocardiographic (ECG) monitoring was assessed in 14 patients (8 males, 6 females; mean age 21 [17-30] years) with the idiopathic long QT syndrome (LQTS), 14 healthy subjects of the same age serving as controls. Twelve patients had the typical history of syncopes or sudden cardiac death among family members; seven patients had a history of syncope, while four patients had been successfully resuscitated. None had associated cardiac disease. Among the group with LQTS the rate-corrected QT interval at rest was 498 + 56 ms, in the control group 412 +/- 30 ms (P < 0.005). Resting and maximal heart rates on exercise were similar in the two groups. The rate-corrected QT interval on exercise was significantly longer in the LQTS patients (P < 0.001). In the control group the maximal heart rate in the long-term ECG was significantly higher (144 +/- 28/min) than in the LQTS patients (128 +/- 17/min; P < 0.01). The long-term ECG recorded abnormal findings in five patients: torsade-de-pointes tachycardia in two, T-wave alternans in two, and bradycardia resulting from intermittent sinoatrial block in one. No abnormal findings were recorded in the control group (P < 0.03).

After extensive animal experiments a new method of high-frequency current coronary angioplasty (HFCA) via a specially developed catheter system was used in ten patients with haemodynamically significant coronary artery stenoses. In eight patients the stenoses affected the anterior interventricular branch (AIVB), in one patient each the circumflex branch and the right coronary artery, respectively. In nine patients the stenosis cross-section was reduced by at least 20% (from a mean of 91.9% +/- 5.8% to 52.6 +/- 17.5%). In three patients HFCA was followed by balloon angioplasty. The total number of applications per patient ranged from 3 to 12 (mean total duration of current flow: 3.9 +/- 1.0 s). There was only one severe complication, in a patient with subtotal AIVB occlusion after initially successful HFCA: balloon angioplasty successfully restored the lumen to the post-HFCA state. The new technique of HFCA is worthy of further development. It promises to be a valuable addition or alternative to balloon coronary angioplasty.

An automatic, implantable cardioverter-defibrillator (AICD) which generates a high-energy current impulse is now available for the management of treatment-resistant malignant ventricular arrhythmias. Such a device (manufactured by Intec/CPI) was implanted into eight patients with coronary heart disease or dilated cardiomyopathy, and in four after surgery for postinfarction ventricular arrhythmias. All patients had had life-threatening episodes of ventricular fibrillation or tachycardia: the arrhythmias were refractory to multiple drug therapy (mean of 6.8 antiarrhythmia drugs per patient). The threshold energy for converting ventricular fibrillation was 9.6 Joules +/- 5.7. Except for one bacterial infection of the electrodes, there were no serious complications. During a mean observation period of 13.6 months 21 electrophysiologically induced and 105 spontaneous tachyarrhythmias were successfully terminated by the AICD. No malfunctions occurred and there was no death due to an arrhythmia.

In a prospective study of 23 patients the clinical effects of rate-adapted activity-sensed (by mechanical resonance oscillations) pacing (Activitrax system) were tested over a mean period of 8.1 +/- 3.8 months. This form of pacemaker treatment was used when, after exercise and on long-term ECG monitoring, the spontaneous heart rate had not exceeded 85 beats per min and there had been symptoms of decreased exercise tolerance. Lasting improvement in physical exercise tolerance was achieved in 11 of 17 patients after changing from fixed-rate to rate-adapted pacing. Treadmill ergometry, randomised in the fixed-rate or rate-adapted mode, brought about a significant rise in exercise tolerance (P greater than 0.01). Contrary to results after external influences, insufficient rate increases in five patients in the course of static stress was of clinical significance and thus narrow the indications for this type of pacing.

The accuracy of ST-segment analysis by means of the Marquette-Laser-Holter system was compared with conventional ECG registration during ergometry. In 26 patients with angiographically confirmed coronary heart disease conventional chest leads and long-term ECGs were recorded simultaneously during standardized exercise. Simultaneously registered ST-segments in V5 and Holter CM5 were compared, with the results correlating well (r = 0.91) for any recorded abnormal repolarizations.

The investigations of ST-segment changes by Holter monitoring demonstrate asymptomatic and symptomatic episodes of myocardial ischemia, which may occur during daily activities. One factor, which is of great importance for the detection of silent myocardial ischemia during ambulatory monitoring, is the combination of the leads. Former studies showed that the analysis of two channels alone may not adequately detect silent myocardial ischemia. We therefore used a three-channel ambulatory ECG monitoring system with a new lead combination. The Holter monitoring results were correlated with the distribution of coronary stenosis detected by coronary angiography. In 54 patients with single coronary vessel disease and ischemic ST-segment depressions during exercise testing, standard Holter lead combination CM2/CM5 was extended by a bipolar Nehb D-like lead. Lead combination CM2/CM5 identified 23 patients (43%) with ST-segment depressions (total number of ischemic episodes = 372). Additional Nehb D-like lead identified 30 patients (55%) with ST-segment depressions (total number of ischemic episodes = 1048). The combination of leads CM2/CM5 and Nehb D raised the number of patients with documented ST-segment depressions to 33 of 54 (61%). Lead Nehb D showed the highest sensitivity for the detection of inferior wall ischemia (stenosis of the right coronary artery); nevertheless, this lead may not be regarded as specific for ST-segment alterations only caused by inferior wall ischemia. The correlation of ischemic ST-segment depressions during exercise testing (classified as anterior, inferior, or anterior and inferior type of ischemia) and documented ST-segment changes in the different Holter leads underline these results. A control group of 40 healthy volunteers demonstrated the high specifity of this new lead combination. In comparison with the standard lead combination CM2/CM5 for the detection of ST-segment changes, lead combination CM2/CM5 extended by a bipolar Nehb D lead is more sensitive for the detection of ST-segment alterations by Holter monitoring.

The Long QT syndrome (LQTS) is a relatively rare disorder. It has a major clinical impact as affected individuals are prone to syncope and sudden arrhythmogenic cardiac death. The LQTS comprises three groups of patients. The Jervell-Lange-Nielsen syndrome is characterized by an autosomal recessive pattern of inheritance and congenital neural deafness. The Romano-Ward syndrome shows an autosomal dominant pattern of inheritance and normal hearing. Patients with the sporadic form of LQTS have no evidence of familial transmission and have normal hearing. Imbalance of sympathetic cardiac innervation with predominance of the left stellate ganglion and an intrinsic myocardial defect leading to early afterdepolarization are the two pathogenetic mechanisms of LQTS discussed today. More recently a genetic basis for the Romano-Ward LQTS has been reported. The genetic linkage to the Harvey ras-1 gene provides the basis for a new hypothesis that an impairment of guanine nucleotide binding proteins is responsible for symptoms observed in LQTS. This paper discusses the genetic basis, pathology and pathophysiology of LQTS and tries to unify the different theories.

The aim of this study was to assess variability of ventricular late potentials (VLP) in patients with and without inducible ventricular tachycardia (VT), and the effects of antiarrhythmic drugs on VLP variability in the high-resolution electrocardiogram (HRECG). In 27 patients 90 s of unaveraged HRECGs were analysed before and 2 h after oral administration of 200 mg disopyramide, 400 mg mexiletine, 300 mg propafenone and 160 mg DL-sotalol. The duration of the QRS (QRSD) and the duration of the terminal low amplitude signal (LASD) was measured from each beat. Beat-to-beat variability was defined as standard deviation of the differences between consecutive beats. Patients with inducible sustained VT (n = 9) showed higher LASD variability than patients without inducible VT (12.3 vs 9.3 ms.beat−1, P < 0.01). Patients with VLP (n = 17), as defined by the signal averaged ECG, also had higher QRSD and LASD variability (11.8 vs 9.5 ms.beat−1, P < 0.05; 11.5 vs 8.2 ms.beat−1, P < 0.01, respectively) compared to those without VLP. All class I drugs lengthened QRSD and LASD in terms of the absolute values, but only propafenone increased QRSD and LASD variability (9.7 to 12.0 ms.beat−1, P < 0.01; 8.9 to 11.9 ms.beat−1, P < 0.01, respectively). In patients with inducible VT, sotalol decrease LASD variability from 14.3 to 9.3 ms.beat−1 (P < 0.05). We conclude that beat-to-beat VLP variability is increased in patients at a high risk of malignant arrhythmias. Further studies are needed to prove whether sotalol-induced reduction of beat-to-beat variability can serve as a non-invasive marker of antiarrhythmic efficacy.

The idiopathic long QT syndrome (LQTS) is an infrequently occurring disorder. It has major clinical impact as patients are prone to syncope, ventricular tachyarrhythmias and sudden arrhythmogenic cardiac death. This paper reports the value of ambulatory electrocardiogram (ECG) monitoring as a diagnostic tool to establish the diagnosis of LQTS. 14 patient with idiopathic LQTS were studied. The results were compared to those of 14 age- and sex-matched healthy control individuals. A 24-hour ambulatory ECG tracing was obtained in each individual. 5/14 patients with LQTS had pathological findings during ambulatory ECG monitoring (2 patients with episodes of torsade de pointes tachycardia, 2 patients with T-wave alternans and 1 patient with bradycardia due to an intermittent SA block), whereas all control persons had normal ambulatory ECG recordings (p < 0.03). Thus, ambulatory ECG recordings may contribute significant diagnostic information in patients with suspected LQTS.

In this study 97 patients with mitral regurgitation (age 62 +/- 11 years, 55 men, 42 women) quantified by angiography were studied using colour flow Doppler imaging of isovelocity surface areas in the flow convergence region proximal to the regurgitant orifice. The radii of the proximal isovelocity surface areas for the flow velocities of 28 and 41 cm/s were measured. A flow convergence region was imaged in 100% (96%) of the patients with Grade I/II or more and in 92% (64%) of the patients with Grade I mitral regurgitation for a flow velocity of 28 (41) cm/s. The radii of the proximal isovelocity surface areas correlated significantly with the angiographic grade in patients with sinus rhythm as well as atrial fibrillation. A correct differentiation of Grade I to II from Grade III to IV mitral regurgitation was provided in more than 90% of all patients for both flow velocities investigated. Assuming hemispheric proximal isovelocity surface areas, in 11 patients the regurgitant volumes from echocardiography (range: 2.6-241 (0.9-198) ml for a flow velocity = 28 (41) cm/s) correlated with, but considerably overestimated the values from cardiac catheterization (range: 1.4-72.5 ml) with r = 0.79 (0.82) (P < 0.01) and SEE = 57.9 (42.4) ml for a flow velocity of 28 (41) cm/s. It was concluded that colour flow Doppler imaging of the flow convergence region enables the diagnosis of mitral regurgitation and the differentiation between Grade I to II and Grade III to IV mitral regurgitation, but may be of little value in estimating the regurgitant volume, assuming a hemispheric symmetry of the proximal flow convergence region.

The purpose of this study was to detect ventricular late fields recorded by a biomagnetic multichannel system in patients with ventricular late potential and to determine the site of these ventricular late fields non-invasively in three dimensions. Biomagnetic signals of sinus beats during a 5-min acquisition period simultaneously recorded by a 37-channel system Krenikon were averaged in all channels. Ventricular late fields were determined in each channel according to the algorithm of Simson for ECG data. For the localization process, baseline correction from the averaged non-filtered signals was performed at the end of the QRS complex under visual control. The single current dipole model within the homogeneous half-space was applied. Eight patients post myocardial infarction with ventricular late potentials (four with recurrent sustained ventricular tachycardia) and four healthy individuals were examined. In the normal subjects, no ventricular late fields were detected. However, ventricular late fields were found in all patients, and were localized in six patients within the border zone of myocardial infarction. In the four patients with ventricular tachycardia, a spatial coincidence of the site of origin of ventricular late fields and the site of origin of ventricular tachycardia determined by catheter mapping was found in two. It is concluded that magnetocardiography is able to detect ventricular late fields and can be used to determine their site of origin.

Life-threatening ventricular tachyarrhythmias are the main reason for sudden cardiac death in coronary heart disease. In the majority of survivors of cardiac arrest, malignant tachyarrhythmias generate from a structurally fixed arrhythmogenic substrate following myocardial infarction without evidence of acute ischaemia. Thrombolysis in acute myocardial infarction improves the electrical stability as elucidated by electrophysiological studies and the signal averaged surface ECG. In post-infarction patients, beta-blockers provide significantly beneficial effects on arrhythmic outcome, particularly in the presence of impaired left ventricular function, whereas calcium antagonists and vasodilators are of no affect or may worsen the prognosis. In survivors of myocardial infarction, the prophylactic use of class I antiarrhythmic agents, which are able to suppress frequent single or complex premature ventricular contractions, cause worsening of the prognosis due to their proarrhythmic properties. However, arrhythmia suppression by antiarrhythmic agents selects patients who are at very low risk for arrhythmic death. Pilot trials using class III antiarrhythmic agents suggest beneficial effect on the reduction of sudden death mortality. As regards secondary prevention of malignant tachyarrhythmias in survivors of ventricular tachycardia or fibrillation, there is controversy about the importance of Holter monitoring or invasive electrophysiological testing in the evaluation of drug efficacy. In patients with severely impaired left ventricular function, pharmacological treatment is of limited efficacy. Even in cases of significant suppression of spontaneous or inducible tachyarrhythmias documented by Holter recording or programmed ventricular stimulation, the arrhythmic outcome is considerably poorer, but it could be influenced by implantable defibrillators. Amiodarone, as a potential alternative to class I antiarrhythmic agents, particularly in patients refractory to conventional antiarrhythmic drugs, shows only limited effects on long-term outcome, which is in part caused by the toxicity of this agent. There is substantial need for new drugs without proarrhythmic properties and particularly for those that correct abnormalities of the automatic nervous system.

Electrical events of the heart can be detected by the conventional surface ECG, however, only depolarization and recovery of the atria and ventricles and the atrio-ventricular conduction delay (P-Q interval) are reflected by the corresponding signals, the P wave and the QRS complex. The activity of the sinus node itself and the His-Purkinje system is buried within the baseline noise because on the body surface their amplitudes are only in the microvolt range. Prolongation of intraventricular conduction of larger myocardial areas can be discovered by the typical hemiblock or bundle branch block patterns of ventricular de- and repolarization, whereas delayed activation of smaller areas of ventricular myocardium, e.g. in the neighborhood of an infarcted area or in right ventricular dysplasia, will be invisible within the conventional surface ECG due to the small amplitude (microvolt level) of the signals of interest1.

The idiopathic long QT syndrome (LQTS) is an infrequently occurring disorder. Affected patients may have electrocardiographic alterations and are prone to syncope and sudden arrhythmogenic cardiac death. Adequate therapy may improve the prognosis of affected patients significantly. Therefore the early and precise diagnosis of LQTS has major prognostic impact. This study reports the diagnostic significance of standard electrocardiographic techniques and autonomic maneuvers in 14 patients with LQTS. The findings are compared with those of 14 healthy age-matched control persons. QTc duration was significantly longer in patients with LQTS during standard 12-lead electrocardiography (489 +/- 56 vs 412 +/- 30 ms, p < 0.005), exercise stress testing (490 +/- 38 vs 409 +/- 18 ms, p < 0.001), cold pressor testing (512 +/- 45 vs 407 +/- 19 ms, p < 0.001), Valsalva maneuver (497 +/- 49 vs 407 +/- 19 ms, p < 0.001), minimal heart rate during 24-hours of ambulatory electrocardiographic recording (482 +/- 69 vs 402 +/- 22 ms, p < 0.01) and maximal heart rate during Holter monitoring (460 +/- 47 vs 411 +/- 27 ms, p < 0.005). Four of 14 patients with LQTS had pathologic findings during ambulatory electrocardiographic monitoring (2 patients with short episodes of torsades de pointes tachyarrhythmia, 1 patient with intermittent sinoatrial block, and 1 patient with intermittent TU-wave alterations), whereas all control persons had normal ambulatory electrocardiographic recordings (p < 0.05). Thus, noninvasive standard electrocardiographic techniques in combination with autonomic maneuvers may contribute significant information for a precise diagnosis in patients with suspected LQTS.(ABSTRACT TRUNCATED AT 250 WORDS)

Summary: This report describes the usefulness of echocardiography in the differential diagnosis of acute cardiovascular events. In a 66-year-old patient with known aortic stenosis and mitral valve prothesis, who suddenly deteriorated with severe dyspnea, a thrombus within the pulmonary artery could be detected with 2-D echo. Pulsedwave Doppler disclosed the resulting flow-velocity disturbances.

Percutaneous excimer laser coronary angioplasty (ELCA) was performed in a first group of 20 patients with stable angina pectoris caused by significant coronary stenosis, and long-term follow-up was evaluated. Prototype 4 to 5.5 French multifibre catheters with 18-20 quartz fibres of 100 microns diameter, concentrically arranged around a central lumen for taking up a guide wire, were coupled to a commercial XeCl excimer laser. Energy was delivered at a wavelength of 308 nm with a pulse duration of 60 or 120 ns. Operating at a repetition rate of 20 Hz, mean energy transmission was 13.4 +/- 6.8 mJ per pulse. In all but one patient the lesion could be passed by the catheter. Percent diameter stenosis decreased from 77.1 +/- 10.8% to 53.1 +/- 11.8% after ELCA. Complications were frequently observed, intracoronary thrombus formation in eight instances, dissection in six patients and spasm in five cases, causing total vessel occlusion in five procedures. All complications could be managed efficaciously by thrombolytic and vasodilating drugs and/or balloon angioplasty. Subsequent PTCA was performed in case of complication or insufficient stenosis reduction after ELCA in 18 patients with adequate results (residual stenosis, 28.5 +/- 10.2%). Long-term follow-up angiography, which could be performed in 16 of 19 laser treatments, demonstrated significant restenosis in only three patients. Our preliminary results suggest that, using ELCA, ablation of atherosclerotic lesions is feasible in most cases. However, compared with PTCA, stenosis reduction is significantly less, and the acute complication rate is much higher. Thus, further improvements of the catheter system are necessary in order to realize the advantages of excimer laser ablation, which can be demonstrated by experimental studies.

In 1977 Andreas Gruntzig performed the first balloon angioplasty in a patient with a critical LAD stenosis [5]. Since that time considerable improvements have been achieved both with the technique itself (steerable guide wires, low profile and super low profile balloons with steerable or fixed guide wires, monorail technique etc.) and the skills of the angio-plasters. Therefore balloon angioplasty in the 1990s has become a standard technique for reduction of significant coronary artery stenoses in patients with coronary heart disease [1,5,9,14]. The acute and longterm results of balloon angioplasty now seem to be standardized worldwide: acute success rate: 80–90%, depending on the coronary artery to be treated and the type of coronary artery lesion; rate of acute complications: about 10%, and that of emergency bypass: 2–5% [1,2], recurrency rate at 3 months: 15–30%, and at 6 months post-treatment about 40–50%.

Since catheter or surgical techniques for ablating the arrhythmogenic substrate in patients with SVT due to accessory pathways or those with VT are now available, exact localization of the substrate is mandatory. We report preliminary results of two new non-invasive techniques for localizing either the site of earliest ventricular contraction using ISPECT, or the site of initial ventricular depolarization by magnetocardiography (MCG) in WPW syndrome and in VT patients. Thirteen patients with WPW syndrome and 8 patients with sustained VTs were studied with ISPECT. In 9/13, comparative catheter mapping data were available. Two patients had two Kent bundles. 13/15 Kent bundles could be localized by ISPECT. In 5/9 patients the area of Kent bundle insertion was identical with ISPECT and catheter mapping, in 3 correlation was fair, and in 2 patients with 2 Kent bundles ISPECT failed to localize their insertion. In 3/8 patients with VT catheter mapping could not be performed for hemodynamic reasons. In 2/5 patients the area of VT focus was identical with both methods, in one patient it was adjacent to each other, and in 2/5 patients a larger anatomic distance of the focus was found with both methods. In 3/7 patients with WPW the MCG showed the site of Kent bundle insertion, which was identical to that seen by catheter mapping. In one patient the area was adjacent, and in 3 more distant from the site determined by catheter mapping. In 1/2 patients with 2 Kent bundles, one of these could be detected by MCG. In 1/3 patients with VT, the site of VT focus was identical with both methods, but in the remaining two a distance of 3–4 cm was observed between the area seen with MCG and that with catheter mapping. In 4 further VT patients with stable and uniform ventricular late potentials, ventricular late magnetic activity was found with different QRS lengths within the single MCG channels. From our results we conclude that both ISPECT and MCG seem to become very promising non-invasive techniques for localizing ectopic ventricular depolarization in WPW syndrome and VT patients. However, these methods have to be refined, improved and validated by further systematical studies.

At time, balloon angioplasty is the well established standard procedure for nonsurgical treatment of coronary stenosis with a success rate of about 90 to 95%. The major limitations of balloon angioplasty such as poor results in recanalisation of chronic obstructed arteries, in the treatment of diffuse atherosclerotic vessels and the high incidence of restenosis [1, 3, 13] are the reasons for the development of alternative techniques like atherectomy, rotational atherectomy and other methods of mechanical revascularisation [4, 12, 18], radiofrequency angioplasty [8], hot balloon angioplasty [19] and different methods of laser applications in peripheral and coronary arteries [6, 19, 20, 21].

Several so-called multiple-action compounds have been developed, such as medroxalol (alpha and beta blockade, and beta-2 stimulation), celiprolol (alpha-2 and beta-1 blockade, and beta-2 stimulation) and carvedilol (beta blockade and vasodilatation) for the treatment of patients with arterial hypertension and with coronary heart disease. Carvedilol exerts relatively uniform peripheral effects, i. e. a reduction of both systolic and diastolic blood pressure at rest and during exercise, and a decrease in the resting and exercise heart rate. Blood pressure fall due to carvedilol may be induced by its vasodilating effect, as documented by measurements of forearm blood flow and peripheral vascular resistance. Moreover, renal hemodynamics does not seem to be significantly altered by carvedilol. Carvedilol may also produce an improvement of the LV contractile status in patients with CHD and impaired LV function, mainly due to afterload reduction, in addition to its antianginal effect, which is due mainly to the beta-blocking properties of this substance. From the studies mentioned it may be concluded that carvedilol is a useful and promising drug for treating patients with both arterial hypertension and with coronary artery disease.

Coronary angiography is the method of choice for documenting the extent and degree of coronary atherosclerotic lesions. Estimating lesion length and degree of stenosis (diameter and cross-section) provides qualitative and quantitative data for estimating the impairment of coronary flow distal to the stenotic coronary artery [2]. However, coronary angiography provides little information about the nature and surface of atherosclerotic plaques, and particularly about additional pathoanatomical processes at the site of the atheroma [1, 25, 27]. Some pathoanatomical postmortem studies have shown that in about 60%–70% of patients with myocardial infarctions thrombotic processes, fissures, and dissections of the atherosclerotic plaques may be present and may account for occlusion of a coronary vessel [3, 4, 6, 7]. Thus, it seems valuable from a clinical point of view to use endoscopic methods to visualize directly the atherosclerotic lesion for documenting such complications.

The extent and degree of coronary atherosclerosis may be assessed by indirect parameters and by direct angiographic measurements. Determinations of the hemodynamic significance and properties of coronary stenoses by classical fluid dynamics, and semi-quantitative evaluation of regional hypoperfusion or abnormalities of metabolism and of regional contractile performance are indirect parameters, that do not provide precise information on progression or regression of coronary atherosclerosis. To obtain reliable and reproducible angiographic measurements of coronary stenoses, angiographic pitfalls (film exposure and processing as well as distance of the patient to x-ray tube and image intensifier must be constant, pincushion distortion must be compensated for, standard reference must be used), physiological variables (respiratory and cardiac cycle and coronary vascular tone must be identical on repeat films, slitlike stenoses must be visualized in different projections), and problems with the measurement procedure itself (reproducibility is important, inter- and intra-observer variability must be minimized, stenosis dynamics and plaque volume can only be quantitated by a computer system) have to be overcome or be compensated for. Using a standardized angiographic protocol, we were able to follow progression and regression in a cohort of 10 patients with familial hypercholesterolemia IIa, who were successfully treated with long-term specific LDL-cholesterol immunoabsorption (LDL-apheresis), that favorably influenced the long-term atherosclerotic activity in the coronary arteries of these patients.

Seventy-nine patients with angiographically documented coronary artery disease were studied with exercise ECG and Holter ECG for ischaemic ST segment changes. Fifty-four patients (68.3%) had ischaemia on exercise, 48 patients (62.0%) had ischaemic ST segment depression during Holter monitoring. Twenty-four (30%) of the patients with a positive exercise test and 30 (61%) with a positive Holter ECG were asymptomatic during the test, 83.7% of the total count of 456 episodes of spontaneous ischemia during Holter monitoring were silent. Forty-four patients (55.7%) had ischaemic ECG changes during exercise and Holter ECG, 20 patients (25.3%) were negative on both tests. Ten (12.7%) had only a positive exercise test and five (6.3%) only a positive Holter ECG. The sensitivity of Holter monitoring for the detection of ischaemia in patients with coronary artery disease is comparable to the sensitivity of the exercise ECG.

The analysis of ST segment changes during Holter monitoring is one important diagnostic method for detection and diagnosis of silent myocardial ischaemia. To assess the specificity and sensitivity of ST segment alterations as a diagnostic tool, 106 healthy medical students (43 females, 57 males, aged 18-36 years, mean age 26 +/- 4 years) and 26 children (14 females, 12 males, aged 12-17 years, mean 14 +/- 3 years) with no history of heart disease and normal findings during physical examination were studied by exercise stress test and Holter monitoring. Criteria for exclusion were a history of hypertension, diabetes mellitus and ST segment alterations during conventional 12-lead ECG. Due to these criteria, eight volunteers had to be excluded from the study. The exercise stress test (maximum work load protocol) revealed no pathological ST segment depressions. During Holter monitoring seven episodes of ST segment depressions (greater than or equal to 1.0 mm planar or downsloping, duration greater than or equal to 1.0 min) were found. Typical ST segment depressions detected by Holter monitoring may be found in healthy subjects. Therefore this finding has to be considered cautiously as a diagnostic tool for evaluation of patients with suspected coronary heart disease.

The feasibility and safety of coronary endoscopy was evaluated in three sets of investigations: in 7 cadaver hearts, in 11 patients undergoing coronary bypass surgery, and in 30 patients during routine cardiac catheterization prior to coronary balloon angioplasty (PTCA). In three of the seven cadaver hearts the lumen of the arteries appeared normal. In three diffuse atherosclerotic lesions, and in one, a high-grade, tight stenosis were observed. In nine of eleven patients in the operation room, the lesions of interest could be visualized, and high-grade stenoses were found in all. In addition, in three patients with unstable angina pectoris, fresh thrombi were seen at the site of stenosis. In six of the nine patients, the periphery of the native coronary vessel was found to have no further stenotic regions. During cardiac catheterization in 17/30 patients, the lesion of interest could be examined angioscopically, and in 13 instances the stenosis appeared excentric and irregularly shaped. In three instances, multiple ulcerations were seen in the stenotic area. In two of the five patients, intimal ruptures were found following PTCA, which could not be documented angiographically. Coronary endoscopy provides valuable additional information on the nature and appearance of atherosclerotic lesions. It can be performed clinically without great harm to the patients. Despite some limitations, it will probably become a routine diagnostic tool in patients undergoing routine coronary angiography, balloon angioplasty or high-frequency angioplasty, and coronary bypass grafting.

To test the clinically supposed development of tolerance during chronic molsidomine therapy we studied a total of 11 patients with angiographically-proven coronary heart disease at rest and during ergometric exercise (supine position; submaximal, i.e. 50 W for 3 min, and maximal exercise). Pulmonary arterial pressure (PAPmean, floating catheter), arterial blood pressure (RR, cuff method), work capacity (W x min) and duration of exercise loading (sec) were measured at rest and on exercise before and during chronic (4 weeks) oral therapy with 3 x 4 mg day-1 of molsidomine. Acute administration of 4 mg molsidomine reduced the mean arterial resting pressure by 12% and under submaximal exercise loading by 8%. After molsidomine, the PAPmean was reduced by 35% at rest; following a period of treatment of 4 weeks no significant decrease in efficacy could be discerned (PAPmean reduction by 31%). Under submaximal and maximal exercise the PAPmean dropped by 44% and 37%, respectively (35.5 +/- 6.7 cf. 19.9 +/- 4.5 mmHg; 39.2 +/- 6.5 cf. 24.8 +/- 7.0 mmHg), whilst simultaneously the work capacity increased by 93% (281 +/- 108 cf. 545 +/- 254 W x min). After 4 weeks treatment with 12 mg day-1 of molsidomine, the PAPmean of 22.4 +/- 6.6 mmHg and 30.1 +/- 9.9 mmHg under identical exercise loading conditions, remained significantly below the exercise load value prior to the onset of medication. The molsidomine-induced increase in the exercise tolerance was maintained throughout the long-term medication (537 +/- 268 W x min). With a four-week treatment with daily doses of molsidomine there was a persistent effect on the pulmonary arterial pressure and the work capacity. Thus development of tolerance during high dose, long-term molsidomine therapy is not to be expected.

On the occasion of a routine medical check-up 256 out of 1100 individuals with an accumulation of coronary risk factors were screened for silent myocardial ischaemia by exercise testing and Holter monitoring. Of these individuals 5.5% had a pathological exercise test, 7.4% had ischaemia-like events on the Holter ECG, 11.3% had at least one pathological test, but only 1.6% had ischaemic signs in both ECG tests. The outcome of the ECG tests appears to be independent of the type and the total number of risk factors. To date, 13 of the 29 individuals with a positive test have undergone thallium myocardial imaging: only three individuals had signs of ischaemia. Holter monitoring and exercise ECG show comparable results in this population. The pathological ECG findings were only partly confirmed by the thallium test. The follow-up will show the prognostic significance of the ECG changes.

In a series of 44 patients, 5 females and 39 males, the incidence and dynamic behavior of ventricular late potentials was studied. Using a home-built high resolution electrocardiogram equipment ventricular late potentials were found within the ST segment in 27/44 patients, and in 11 patients were the late potentials observed intermittently. In 21/44 patients late potentials were also present after the T wave, in 5 individuals intermittently.

Pacemaker patients have been reported to suffer from heart related symptoms in about 10 to 60% of cases after implantation [1-3]. For the differential diagnosis of arrhythmias or pacemaker dysfunctions as possible causes of such complaints, provocative tests and 24 h-Holter-ECG have been proposed [4-6]. Ambulatory longterm ECG recording allows the detection of infrequently occurring pacing events and the assessment of the spontaneous incidence and the severity of pacemaker dysfunctions inducible by provocative tests. This allows an estimation of the individual clinical relevance of very commonly provocable pacemaker reactions, such as inhibition of the pacemaker spike delivery caused by isometric muscle contraction which has been reported in 11-77% of pacemaker patients [7-9]. Retrograde V-A conduction, a possible cause of tachycardias in dual-chamber devices, has been described in 47-95% of patients at the time of the pacemaker implantation [10,11]. Beside detection of dysfunctions Holter-ECG allows the assessment of the underlying rhythms and background arrhythmias.

In patients with chronic recurrent attacks of supraventricular, and in rare cases of ventricular tachycardia, chronic antitachycardia pacing using implantable pacemakers with different termination modes may be an attractive alternative to chronic drug therapy, particularly in patients with drug refractoriness or serious side effects. Before implantation of an antitachycardia pacemaker various clinical and technical conditions have to be considered and tested, such as reproducibility of tachycardia termination, effective and safe termination mode, optimal lead position, conditioning of the tachycardia by antiarrhythmic drugs for safe electrical termination, and the possible deterioration of the tachycardia by the antitachycardia pacing mode itself.

Long-term treatment of patients with recurrent attacks of ventricular tachycardia (VT) and an increased risk of sudden death may be crucial, since in some patients antiarrhythmic drugs may be ineffective or may induce serious side effects. Thus, endo-epicardial cardioversion-defibrillation seems an attractive alternative for short-term, and probably also long-term treatment of recurrent VT and ventricular fibrillation (VF).

Since it’s introduction into clinical cardiology PTCA proved to be an effective method for reduction of coronary stenoses, thus leading to relief of angina pectoris and an increase of exercise tolerance in CHD patients. The success rates of PTCA depend on the type of lesion, catheter material, experience of the angiographer, and on the inflation pressure and inflation time used. With longer inflation times possible hazards of PTCA-induced ischemia may arise like LV pump failure or the occurrence of dangerous ventricular arrhythmias. Myocardial protection during PTCA may be achieved by means of intracoronary (ic.) administration of Nitro glycerine and/or Nifedipine (or other calciumantagonists as well) prior to inflation, or by simultaneous perfusion of the dependent myocardial area with arterial blood during the whole inflation period. Several studies using ic.-Nitroglycerine and/or Nifedipine have shown that sometimes symptoms and particularly signs of myocardial ischemia on PTCA may be delayed by these drugs and the occurence of ventricular arrhythmias decreased, thus allowing potentially longer inflation periods. On the other hand, using quantitative LV angiography we could demonstrate that the impairment of global and regional LV contraction due to PTCA-induced ischemia was considerably and significantly less pronounced when using simultaneous perfusion with arterial blood during inflation. Administration of Nitroglycerine and/or Nifedipine by ic.-route seems to be a simple, rapid and safe method of myocardial protection from PTCA-related ischemia, but it may not preserve LV global and regional performance to such a degree as could be achieved using perfusion with arterial blood. The perfusion method may, therefore, provide the opportunity to also attempt PTCA in patients with multiple vessel disease and severely impaired left ventricular perfomance, as well as in individuals with left main stenoses.

In 70 patients (3 females and 67 males), aged 16-72 years (mean: 51 +/- 9 years), the low noise ECG was recorded from body surface by the signal averaging and the high resolution beat-to-beat techniques. We found 61 patients were suffering from coronary heart disease, 4 had atypical coronary heart disease (syndrome X), 4 had dilatative cardiomyopathy, and one had the long QT syndrome (Romano-Ward syndrome). We found the following recovery rates for ventricular late potentials within the ST segment with the averaging technique: clearcut in 13/53 patients, doubtful in 16/53 patients, and late potentials absent in 26/53 patients. With the beat-to-beat technique the following recovery rates were found: clearcut late potentials in 27/70 patients, doubtful in 23/70 patients, none in 20/70 patients, and intermittently occurring late potentials in 18/70 patients (categorized as doubtful late potentials). When comparing the detection of late potentials with both methods in individual patients, we found concordant results in 39/53 patients studied (positive with both methods in 24/53 patients, negative with both methods in 15/53 patients), and discordant results in 14/53 patients (positive with the beat-to-beat technique and negative with the averaging technique in 12 individuals, negative with the beat-to-beat technique and positive with the averaging technique in the remaining 2 patients). The correlation between the incidence of late potentials and the presence of exercise-induced myocardial ischemia (submaximal bicycle exercise) was higher when using the high resolution beat-to-beat technique, as holds also true for the correlation to complex ventricular arrhythmias.(ABSTRACT TRUNCATED AT 250 WORDS)

Balloon dilatation (PTCA) at present seems to be the standard procedure for nonsurgical coronary angioplasty in patients with clinically significant stenoses (3, 5). Despite relatively high initial success rates of up to 90% and more (1), there are many patients with stenotic lesions (e.g., eccentric, calicified or longsized) that seem to be unsuitable for balloon dilatation. Moreover, recurrency rates after initial successful PTCA are in the range of 20% –30%. This may in part be due to a traumatization of the vessel intima by the balloon inflation, which may cause the release of aggregatory and vasoconstrictor substances, as well as of proliferatory factors that result in growing of the atheroma at the site of foregoing PTCA. Lastly, with balloon angioplasty atheromatous material will not be removed or condensed as could be accomplished by atherectomy or thermal angioplasty. Therefore alternative methods of coronary angioplasty are being developed, among which radiofrequency angioplasty (4) and laser angioplasty (8) seem to be the most effective and attractive methods. Based on experimental results with radiofrequency thermal recanalization of thrombotically occluded arteries in domestic pigs (4), we have designed a new catheter system for radiofrequency coronary angioplasty in patients with hemodynamically relevant coronary artery stenoses.

Endocardial right and left ventricular mapping was performed in n = 12 patients with the Long QT Syndrome (LQTS) to determine the presence of my-ocardial microvolt potentials (MMP) within the ST-T segment and after the T-wave. The findings were compared with those obtained in n = 12 age and sex matched WPW patients, who served as control group. Mapping was performed without medication (baseline), and after Orciprenaline (0.01 mg/kg i.v.) and Propranolol 0.013 mg/kg i.v.). LQTS Control P QTc-duration Baseline 479 ± 41 ms 395 ± 29 ms l0.01 Orciprenaline 494 ± 43 ms 386 ± 24 ms l0.01 Propranolol 461 ± 48 ms 397 ± 26 ms l0.01 MMP Baseline n = 3 n = 0 NS Orciprenaline n = 12 n = 0 l0.01 Propranolol n = 0 n = 0 NS MMP could be detected in all LQTS patients after administration of Orciprenaline, no MMP could be induced in the WPW group. We consider MMP in LQTS patients to be an evidence of early after depolarizations. This finding could be pathognomonic for LQTS patients. Thus, endocardial mapping may contribute important diagnostic information in patients with suspected LQTS.