Quadricuspid pulmonary valve and left pulmonary artery aneurysm in an asymptomatic patient assessed by cardiovascular MRI.

We present a coincidental finding of quadricuspid pulmonary valve and left pulmonary artery aneurysm. As both the pulmonary valve and the pulmonary trunk with its main branches are hard to visualise with cardiac ultrasound, most abnormalities described so far are from autopsy series. With the increasing use of CMR and its excellent potential for visualising both pulmonary valve and pulmonary arteries, we believe more cases will be discovered in the near future. Although pulmonary artery aneurysm are rare, timely detection may prevent lethal bleeding.

Effects of intracoronary thrombolysis on global left ventricular function assessed by an automated edge detection technique.

Three hundred and two patients with acute myocardial infarction were enrolled in a randomized multicenter trial to compare conventional treatment with attempted recanalization by intracoronary streptokinase. In a subgroup of patients, the effects of thrombolysis on left ventricular function were evaluated within 48 hr, at 2 wk, and at 3 mo after admission. Global left ventricular ejection fraction (LVEF) was obtained by radionuclide angiography and analyzed with an automatic detection program. Paired data were determined in 160 patients (control 78, thrombolysis 82) within 48 hr and at 2 wk, and in 143 patients (control 71, thrombolysis 72) at 48 hr, 2 wk, and 3 mo. It was shown that LVEF significantly improved in the thrombolysis group as compared with controls both at 2 wk (delta LVEF thrombolysis 3.9 +/- 7.9%, p less than 0.001 compared with delta LVEF control 0.6 +/- 9.7%, p = N.S.) and at 3 mo (delta LVEF thrombolysis 3.1 +/- 12.4%, p less than 0.05 compared with delta LVEF control 2.1 +/- 12.2%, p = N.S.). When patients were divided according to infarct site, however, significant improvement at 3 mo was only observed in the patients with anterior infarction (delta LVEF thrombolysis 5.5 +/- 13.1%, p less than 0.05 compared with delta LVEF control 3.3 +/- 10.4%, p = N.S.). It was shown that acute intervention with intracoronary streptokinase has a potentially favorable and lasting effect on left ventricular function in patients with anterior myocardial infarction. This improvement might be related to the rather rapid administration of thrombolytic therapy with a median time of approximately 4 hr after onset of symptoms.

Usefulness of combined two-dimensional echocardiography and transesophageal atrial stimulation early after acute myocardial infarction.

Transesophageal atrial stimulation (TRAS) was combined with 2-dimensional echocardiography in 69 consecutive patients on days 3 to 5 (mean 3.3) of their first, uncomplicated myocardial infarction, to determine if inducible remote asynergy (i.e., not directly adjacent to the infarcted area and supposedly related to another vascular territory) provides information regarding (1) extent of coronary artery disease, and (2) future ischemic events. Uncomplicated, adequate stress studies were performed in 59 of 69 patients (86%); all these patients had regional asynergy at rest. Remote asynergy at rest was present in 7 patients and during TRAS in 26 patients. Coronary angiography was performed within 2 to 3 weeks after the acute phase. Multivessel disease was present in 23 of these patients and absent in 3. Of the 33 patients without remote asynergy during TRAS, 5 had multivessel disease. Sensitivity of remote asynergy during TRAS for detecting multivessel CAD was 82%, specificity 90%, and predictive accuracy 86%. New ischemic events, defined as recurrent infarction, cardiac death, or revascularization within 12 to 18 months (mean 12.6) occurred in 24 patients (41%); remote asynergy during TRAS was present in 16 of these patients (67%). It is concluded that TRAS combined with 2-dimensional echocardiography can safely be performed in the early days of acute myocardial infarction; remote asynergy during TRAS reliably identifies patients with multivessel disease and future ischemic events.

Usefulness of two-dimensional exercise echocardiography shortly after myocardial infarction.

To determine the clinical significance of transient remote asynergy after the first acute myocardial infarction (AMI), 2-dimensional echocardiography was performed at rest and directly after dynamic exercise in 49 consecutive patients within 3 weeks of AMI. In 43 patients (88%), technically adequate 2-dimensional echocardiographic examinations were obtained. Asynergy was found in all patients at rest. Immediately after exercise, new areas of asynergy, not adjacent to the infarcted area (i.e., transient remote asynergy), were present in 18 patients. Of these patients, 17 had multivessel coronary artery disease (CAD), compared with 5 of 25 patients without transient remote asynergy. Sensitivity of transient remote asynergy for detecting multivessel CAD was 77% and specificity was 95%. Left ventricular ejection fraction at rest and after exercise was measured in 39 patients (90%) and could only identify patients with 3-vessel CAD. New ischemic events, defined as reinfarction or recurrent angina pectoris, within a mean of 12 weeks (range 8 to 16) after discharge, occurred in 16 patients. Transient remote asynergy was present in 12 of these patients (75%). It is concluded that exercise-induced transient remote asynergy early after AMI can identify patients with multivessel CAD and a subgroup of patients prone to early new ischemic events. Left ventricular ejection fraction, however, is not only more laborious but also of lesser value in identifying patients with multivessel CAD.

Prognostic implications of regional hyperkinesia and remote asynergy of noninfarcted myocardium.

To determine the clinical significance of regional hyperkinesia and remote asynergy of noninfarcted areas in patients with a first acute myocardial infarction (AMI), 2-dimensional echocardiography was performed in 113 consecutive patients within 12 hours after admission to the coronary care unit. In 98 patients (87%) all segments of the left ventricular wall were recorded. Infarct-associated asynergy was anterior in 63 and inferior in 35 patients. Regional hyperkinesia was present in 66 patients (67%)--44 of 63 with anterior (69%) and 22 of 35 with inferior (63%) infarcts--and was more frequently seen in patients with 1- and 2-vessel coronary artery disease (CAD) than in patients with 3-vessel CAD (87 and 72% vs 25%, p less than 0.001). In contrast to enzymatic infarct size, absence of regional hyperkinesia was significantly associated with a higher left ventricular wall motion score (p less than 0.01). Twenty patients died within 30 days after onset of AMI; in 15 (75%) regional hyperkinesia was absent. Absence of regional hyperkinesia, especially in anterior infarcts, was associated with a high mortality rate (13 of 19 patients [68%]). Remote asynergy, i.e., not adjacent to the infarct area and supposed to be related to another vascular region, was present in 17 of 98 patients (17%)--11 of 63 with anterior (17%) and 6 of 35 with inferior (17%) infarcts. Remote asynergy was present only in patients with multivessel CAD and was significantly related to a higher wall motion score (p less than 0.001), but not to enzymatic infarct size.(ABSTRACT TRUNCATED AT 250 WORDS)

Pneumothorax resulting from subclavian puncture: a complication of permanent pacemaker lead implantation.

Pneumothorax is a mild complication during pacemaker lead implantation using the subclavian puncture technique. We report on five-year experience in 433 pacemaker lead implantation procedures in 379 patients. The cephalic vein route was solely used in twelve patients. Three procedures were performed over time in four patients and one patient needed four repetitive punctures for pacemaker lead implantation and replacement. Thus 421 punctures were carried out in 367 patients. Eleven case of pneumothorax were observed: in eight patients (1.9%) a partial pneumothorax occurred and in three patients (0.7%) the pneumothorax was nearly complete. In the latter patients a chest tube was inserted and hospital admission was prolonged for 3, 6 and 6 days, respectively. Old age with a corresponding abnormality in the form of chest deformation were predominantly found in the patients with this type of complication.

The role of remote monitoring in the reduction of inappropriate implantable cardioverter defibrillator therapies.

Implantable cardioverter defibrillators (ICDs) with the integrated Home Monitoring feature use dedicated mobile phone and internet links to provide the physicians and technicians in the ICD clinic with the essential device- and arrhythmia-related data stored in the ICD diagnostic memory. Various counters, graphs and intracardiac electrograms are automatically transmitted via Home Monitoring each day to allow prompt, remote presentation of arrhythmias or detection of technical problems. One of the most inconvenient side-effects of the ICD therapy is inappropriate intervention of the device. Home Monitoring data can help the physician to identify and subsequently reduce the incidence of inappropriate ICD therapy.

First results of the Canadian and European Single lead DDD Studies. A report of two multicenter studies on Vena Cava Atrial Stimulation (VECATS).

The first results of a new, single lead DDD pacing system consisting of two bipolar combinations of floating atrial ring electrodes, with the proximal ring at the vena cava superior junction, and which can be used separately for atrial sensing and pacing (VECATS) are reported. Uncomplicated implantation of the pacing system was performed in 78 patients with VDD indications. Pacing and sensing parameters were measured at implantation, before discharge (days 1-3), at 1 and 3 months in various positions and during activity. Atrial pacing threshold (AT) and diaphragmatic stimulation threshold (DT) were 3.3 +/- 1.1 V and 7.2 +/- 2.2 at implant, and 4.3 +/- 0.5 and 7.9 +/- 1.1 V at 3 months, respectively, in the European group. In the Canadian group AT increased and DT decreased during follow-up, leaving a safety margin of 1 V. Reliable intraoperative atrial pacing was possible in 93% of patients. Failures were caused by no capture (3%) or AT > DT (4%). At 3 months, 54% of the atria were consistently paced. Atrial pacing failures were due to no atrial capture (8%), and AT > DT (38%). We conclude that atrial pacing was safe and initially possible in the majority of patients with the VECATS pacing system, though diaphragmatic stimulation became more prevalent over time, due to an increase in AT threshold and a decrease in DT.

Home monitoring in ICD therapy: future perspectives.

The expanding indications for ICD therapy and the complexity of current devices will have impact on follow-up policy. The application of ICD therapy requires elaborate attention to technical aspects, arrhythmias, and the clinical course of the underlying disease. Currently, the quality of medical supervision is dependent on scheduled regular follow-up visits. A disadvantage of long intervals can be a delay in the physician's or patient's awareness of changes in the clinical status. Some patients will need more intensive follow-up while others will have the device as a stand-by and only need technical follow-up. A possibility to address this situation, is the transmission of data, already stored in the implanted device. This will guarantee continuous patient surveillance and could possibly help to avoid unnecessary follow-up visits.

Transesophageal atrial pacing--stimulation and discomfort thresholds: the role of electrode configuration and pulse width.

A balloon catheter with six electrodes has been developed for transesophageal atrial stimulation of the human heart. Introduction is easy and its positioning is simple with the help of six unipolar atrial electrograms. In a group of 20 healthy volunteers, stimulation and discomfort thresholds (intolerable discomfort) were measured for three levels of pulse widths (12, 16, and 20 msec) and for five electrode configurations. Stimulation thresholds were below discomfort thresholds in each case. The stimulation threshold depended on pulse width and not on electrode configuration. The discomfort threshold, however, depended on the electrode configuration and not on the pulse width. A moderate but potentially important increase of the ratio between stimulation threshold and discomfort threshold could be achieved by combining a long pulse width (20 msec) and avoiding the largest distance between the active (cathode) and the passive (anode) electrode. Transesophageal atrial stimulation promises to be a practical noninvasive tool for the termination of regular supraventricular tachycardias, basal electrophysiological studies, and controlled acceleration of the heart rate in the study of myocardial ischemia.

Entrapment of tined leads.

A rare complication is described, in three patients. The tined tip of a ventricular pacemaker electrode was entrapped in the chordae of the tricuspid valve and could not be removed by subtle manipulations in two patients. In one patient, the electrode was removed with partial rupture of the tricuspid valve. The two electrodes remained in the entrapped position and new electrodes were inserted in all three cases. No clinical sequelae were found during follow-up of at least 24 months.

The optimal oesophageal pacing technique--the importance of body position, interelectrode spacing, electrode surface area, pacing waveform and intra-oesophageal local anaesthesia.

In order to improve the technique of transoesophageal atrial stimulation (TAS), the effects of body position, interelectrode spacing and electrode surface area on pacing threshold were assessed in two substudies. The effects of intra-oesophageal local anaesthesia and of two different pacing wave configurations on pacing threshold and discomfort were also assessed. Substudy I comprised 16 subjects (3 patients with a history of paroxysmal supraventricular tachycardia and 13 healthy volunteers) and substudy II comprised 16 healthy volunteers. TAS was performed using a hexapolar luminal prototype oesophageal electrode catheter. In substudy I bipolar pacing was performed in the semi-supine and left decubitus body positions for different pulse durations (20, 10, 6 and 2 ms), interelectrode pole distances (10 to 24 mm) and electrode pole surface areas (0.22 to 0.66 cm2). In substudy II TAS was performed with square wave and triangular waveform pulses after intra-oesophageal saline and lidocaine 20 mg/ml. These solutions were given in random order. Neither the interelectrode distance nor electrode surface areas had any significant influence on pacing thresholds. Stimulation thresholds were not affected by body position. Intraoesophageal lidocaine did not affect the discomfort experienced. Peak pacing thresholds using a triangular waveform were significantly higher than thresholds using a square waveformn (p < 0.001). The optimal pacing technique for TAS remains to be defined. The TAS-induced pain is probably not generated from the oesophageal mucous membrane. There is a significant difference in pacing thresholds between triangular and square waveforms.

Three-year experience with a stylet for lead extraction: a multicenter study.

INTRODUCTION: The extraction of chronically implanted and infected pacemaker and defibrillator leads is an important issue. This article describes the experience gathered between 1990 and 1994 by seven European centers regarding a locking stylet that is uniformly applicable for a wide variety of internal pacing coil diameters. This interventional locking stylet for lead extraction has an outer diameter of 0.4 mm (0.016 inches). The stylet consists of a hollow shaft in which an inner traction wire is embedded. At the tip of the inner traction wire an anchoring mechanism, which can be opened by retraction, is applied. Removal attempts were made for 150 leads, 110 in ventricular and 40 in atrial positions. RESULTS: Complete removal was possible in 122 cases (81%). Partial removal was possible in 18 cases (12%). Failure to remove the lead with the extraction stylet was experienced in 10 cases (7%). In seven patients, the leads were removed by cardiothoracic surgery; 3 defective leads were left in place. There were no serious complications associated with the procedure. None of the patients died. CONCLUSION: The experience with this extraction stylet for lead removal has shown good results. Despite a low complication rate thus far, each case for lead removal should be judged on the individual basis of benefit-to-risk ratio.

Cardiovascular responses, arterial oxygen saturation and plasma catecholamine concentration during upper gastrointestinal endoscopy using conscious sedation with midazolam or propofol.

Hypoventilation as a consequence of deep intravenous sedation is the most frequently reported cause of cardiac arrest during upper gastrointestinal endoscopy (UGIE). Haemodynamic stress can contribute to myocardial ischaemia; therefore, this study was designed to observe prospectively the cardiorespiratory changes during UGIE using either midazolam or propofol for conscious sedation. Thirty-four patients, aged 50 years and older, ASA physical status I-III, scheduled for elective UGIE with sedation, were studied. Oxygen saturation, heart rate, non-invasive blood pressure and Holter ECG were recorded continuously starting 15 min before sedation until 15 min after the endoscopy. In addition, plasma catecholamine concentrations were determined. The results of this study are consistent with previous reports that cardiopulmonary events may occur during endoscopy, with or without sedation. Both midazolam and propofol sedation may provide some protection against haemodynamic stress in response to insertion and manipulation of the endoscope, but sedation can also contribute to the occurrence of hypoxaemia.

CRAVT: a prospective, randomized study comparing transvenous cryothermal and radiofrequency ablation in atrioventricular nodal re-entrant tachycardia.

BACKGROUND: Transvenous catheter ablation of atrioventricular nodal re-entrant tachycardia (AVNRT) with radiofrequency (RF) is effective and safe, but carries a 1-3% incidence of early and potentially late heart block. Cryothermy can create transient effects, and identify potentially successful ablation sites and decrease the risk for permanent heart block. METHODS: In this prospective, randomized trial 102 patients with recurrent narrow QRS-complex tachycardia suggestive of AVNRT were randomized to either RF or cryoablation before a diagnostic study. RESULTS: In 63 patients with AVNRT, 33 were randomized to RF and 30 to cryoablation. Procedural success was achieved, respectively, in 30 (91%) patients in the RF and 28 (93%) in the cryoablation group. The median number of cryothermal applications was significantly lower than the number of RF applications (2 versus 7, p<0.005). No accelerated junctional rhythm was seen with cryothermy, while it was present in 31/33 RF patients. Both fluoroscopy and procedural times were comparable. The radiological position of the successful site in relation to anatomical landmarks was slightly different (p<0.05). No cryothermy related complications were observed, and no permanent AV conduction disturbances occurred. During a mean follow up of 13+/-7 months long-term clinical success was seen in one additional patient in each group. In the same period, 3 patients in both groups experienced recurrent AVNRT. CONCLUSION: Cryoablation is as effective and safe as RF for AVNRT. Significantly fewer applications are necessary, with comparable procedure times. This makes cryothermy useful for the treatment of tachyarrhythmias near the compact AV node.

P wave recognition and atrial stimulation with fractally iridium coated VDD single pass leads.

UNLABELLED: The bottleneck of VDD systems is the reliable detection of the small atrial signals by a floating atrial electrode. Fractally iridium coated electrodes offer excellent sensing and pacing performance. In this study, the performance of such a floating atrial lead in P wave sensing and synchronous ventricular stimulation was examined. Atrial pacing was also used as a test of atrial wall contact. PATIENTS AND METHODS: A fractally iridium coated VDD lead was implanted in 18 patients. In 15 patients it was interfaced with a VDD pacemaker and in 3 patients with a DDD system depending on the P wave amplitude measured acutely (> or = 2 mV). Simultaneous recordings of the surface ECG and pacemaker telemetry were used to analyze P wave amplitudes and AV synchrony in different body positions, and during normal and deep breathing. Additionally, exercise tests based on daily life activities and 24-hour ECG monitoring were performed to test the pacemaker function. RESULTS: During implantation P wave amplitudes were 1.86 mV +/- 1.08 mV (range 0.5-4.9 mV) and during follow-up (6.6 +/- 5.6 weeks) 0.18-3.8 mV. Holter recordings revealed reliable P wave sensing at a sensitivity setting of 0.5 mV (95.5%). P wave sensing was further improved by a higher atrial sensitivity. AV synchronous pacing > or = 99.9% was achieved in all patients. In 7 patients the atrial electrode could be positioned close to the atrial wall enabling atrial stimulation thresholds at an average of 4.3 volts. CONCLUSION: This fractally iridium coated VVD lead allowed consistent and reliable P wave sensing at an atrial sensitivity as low as 0.5 mV in selected patients.

Acute haemodynamic effects of endralazine in patients with coronary artery disease and stable angina pectoris.

The acute haemodynamic effects of endralazine, a new hydralazine-like vasodilating agent, were studied in 6 patients with stable angina pectoris and proven coronary artery disease. Twenty minutes after intravenous administration of 5 mg endralazine heart rate and cardiac index increase, while mean arterial blood pressure and total systemic resistance were significantly reduced. Three patients developed symptoms of typical angina pectoris 15 to 20 minutes after drug administration, probably caused by reflex tachycardia. We conclude that intravenous administration of endralazine causes marked haemodynamic effects for the drug is a potent arterial vasodilator, but it may precipitate anginal chest pain in patients with coronary artery disease.

Testing a new mechanism for left interventricular septal pacing: the transseptal route; a feasibility and safety study.

AIMS: To prove the feasibility and safety of left interventricular septal pacing. BACKGROUND: Right ventricular apical pacing is an established but haemodynamically less favourable pacing method compared with transvenous left ventricular pacing. Alternatively, we propose a simple septal screw-in lead for left interventricular septal pacing. METHODS: A pacemaker lead with a long insulated screw with the two distal windings forming an active tip was implanted from the right side of the interventricular septum to the subendocardial left side in six goats. A special guiding sheath enabled stable, easy, and swift implantation of the lead. The implantation was performed using fluoroscopy together with. normal and contrast echocardiography (via the long pre-shaped sheath) and electrocardiographic signals (His-bundle recordings in conjunction with atrial and ventricular intracardiac signals). The screw was also positioned at other locations along the free wall, and at the interventricular septum to assess possible adverse effects at other sites. RESULTS: An average of 2.2 +/- 1.5 positions per goat was attempted. No adverse effects were noticed during implantation or at necropsy. In two goats, the final position was at the junction of the right ventricular wall and the interventricular septum. Parameters at the final positions were as follows: the pacing threshold was 1.3 +/- 1.0 V at 0.5 ms; the pacing impedance was 1022 +/- 463 omega at 4.8 V and 0.5 ms. R-wave amplitudes were 17.6 +/- 7.6 mV. CONCLUSION: Left interventricular septal pacing is feasible. In our study it was safely performed in six goats. The pacing threshold was low, and the stability of the lead system was good. Implantations in humans and animals and haemodynamic evaluations are needed to reveal the potential benefits of this new form of left interventricular septal pacing.

Prediction of spontaneous coronary reperfusion in myocardial infarction.

To investigate the possibility of predicting the occurrence of spontaneous coronary reperfusion in acute myocardial infarction we studied 91 patients in a randomized trial on the clinical efficacy of intracoronary streptokinase compared to conventional treatment. Of the 46 patients treated conventionally 40 had catheterization 6 weeks after the infarction. Spontaneous coronary reperfusion was found in 19 patients (48%). The time to peak CK-MB in these patients was considerably longer than in patients with streptokinase-induced coronary reperfusion and similar to the time in patients without spontaneous coronary reperfusion. Spontaneous coronary reperfusion was associated with a relative improvement of radionuclide ejection fraction from day 1 to day 14 after admission. There was no difference in the occurrence of ventricular arrhythmia or recurrent ischaemic events between the patients with and those without spontaneous coronary reperfusion. Thus, spontaneous coronary reperfusion is not uncommon in traditionally treated myocardial infarction, but its occurrence cannot be predicted by enzymatic or clinical parameters.