Search

Body surface potential maps (BSPMs) recorded during pace mapping provide an important non-invasive means for identifying local cardiac events; recent clinical studies demonstrated that endocardial pacing sites can be resolved within less than 10 mm. We sought to determine whether similar spatial resolution could be achieved during epicardial pacing. Four patients who were undergoing either heart valve replacement (one), aortocoronary bypass graft (one), or both (two) were studied. In each patient, a pair of epicardial electrodes was placed intraoperatively at the middle aspect of the right ventricular free wall. The distance between the neighbouring electrodes was 10 mm. Five days after the surgery, ECGs were acquired from 35 leads during pacing from each epicardial electrode. We determined the distributions of QRS integrals (the net area under the ECG signal) and compared integrals corresponding to pacing from each of the adjacent electrodes using statistical indices. Student's t-test was applied to these indices and in all the patients revealed that differences in distributions of QRS integral maps were statistically significant (p < 0.01). Results of our study indicate that the non-invasive acquisition of body surface ECGs could resolve epicardial breakthrough sites within 10 mm, which may be useful in facilitating therapeutic ablations in patients with ventricular tachycardias.

Telemedicine is declared as delivery of care to patients anywhere in the world by combining communications technology, with medical expertise. The well established applications of telemedicine are in the field of teleradiology, pathology, cardiology. In some cases video-conferencing (VC) may be applied. Second medical opinion is an important additional viewpoint on the patient diagnosis and treatment. The established network of consultant hospitals and worldwide Second opinion centers enable a fast (24-72 hours response) second medical opinion consultation service with the telemedicine application. The consultant hospitals at present time are: UCSF--San Franscisco, Stanford Medical Center, Bowman Gray School of Medicine, The Brigham Radiology Foundation, Emory University Hospital, University of Pennsylvania Medical Center. The second opinion centers are located worldwide, just to mention some of them: London, Budapest, Ljubljana, Tel Aviv, Bombay, Athens, Milano, Seoul.

Transtelephonic ECG has been introduced in Slovenia in 1996. It has been operating on a regular basis since September 1997. Users of the system are health institutions and patients with CV diseases. They use portable 12-channel ECG weighing less then 200 grams. Diagnostic center is located in medical ICU in Clinical Center Ljubljana. In the first 20 months of regular operation we have received 852 calls, 450 of them being diagnostic. The most common reasons for calling were: ischaemic chest pain, atypical chest pain, palpitations and dyspnoea. Most common diagnoses made on the basis of history and ECG were: AMI, angina pectoris, paroxysmal tachycardias and atypical chest pain. In 186 cases the cardiologist's advice sufficed, 171 patients were referred to the ER, 142 immediately and 29 only if suggested therapy hadn't been successful. To 82 patients new medication or changed dosage of previous medication was suggested. With the intent to evaluate accuracy of the diagnoses made on the basis of history and transtelephonic ECG evaluation we followed up the patients who were sent to ER in Ljubljana upon our cardiologists' advice. On the basis of preliminary results we can conclude that TTE is as diagnostic as the conventional ECG and its' use shortens time from onset of symptoms to initiation of treatment, it lowers disability and mortality due to CV diseases and improves cost benefit.

Background: We used novel equipment for measuring the direct tip pressure (P) of a clamp arm on the vessel wall and studied the relationship between endothelial injuries and various clamping pressures., Methods: A strain gauge was applied to the surgical clamp arm and connected via amplifier to a 12-bit analogue-digital converter on a PC--MSDOS computer. In the on-line in vivo measurements on rat thoracic aorta a momentary peak clamping pressure (MPCP) as well as the lower stationary clamping pressure (SCP) was defined. Clamping forces of two clamps commonly used in cardiovascular microsurgery were tested in the experiment on rat thoracic aortas: clamp A had the tip pressure p = 0.60 N/mm2 and clamp B p = 5.16 N/mm2. After 15 minutes of occlusion, the thoracic aorta was excised and scanning electron microscopy studies for aortas clamped with clamp A and clamp B were performed., Results: Great endothelial lacerations with complete disruption of the endothelial layer in the rings clamped with the clamp B were seen, but no disruption in rings clamped with clamp A., Conclusions: The clamping vessel wall injuries, particularly in endothelial layers, depend on the momentary peak clamping pressure as well on the lower stationary clamping pressure.

Background: The contraction/relaxation response of thoracic aortal rings clamped with two clamping pressures to KCl, noradrenaline and carbachol was studied., Methods: Clamp A had the tip pressure PA = 0.60 N/mm2 and clamp B PB = 5.16 N/mm2. In fifteen Wistar albino rats, weighing 328 +/- 19 g (mean +/- SD) the thoracic aorta was occluded for 15 minutes and then three vascular rings (2 mm wide) were excised. The proximal unclamped ring served as a control. From distal rings the diameter of the aorta was calculated from their circumference 1.61 +/- 0.01 mm (n = 15, dmin = 1.51 mm, dmax = 1.70 mm). The rings were challenged with cumulative additions of KCl (10-80 mmol/l) to measure the contraction. Then cumulative relaxation to carbachol (0.01-100 mumol/l) as a response to noradrenaline precontraction (0.1 mumol/l) was determined., Results: A significant loss (p < 0.05) of vascular relaxation in all clamped rings (clamped with PA and PB clamping pressures) was seen. No significant differences (p > 0.05) were observed for contraction between clamped and control rings clamped with clamp A, however the rings clamped with clamp B showed a significant reduction in contraction (p < 0.05). No significant differences were seen from control rings between groups A and B (p > 0.05), or from clamped rings between groups A and B (p > 0.05) for both the contraction and relaxation part of experiments., Conclusions: Endothelial vascular layers are much more susceptible to pressure injuries than was previously believed.

We report the case of a 33-year-old man after knee luxation and disruption of a popliteal artery, which was missed after repositioning at the first clinic. Eighteen hours later complete discontinuity of the popliteal artery was confirmed by arteriography and an immediate reversed, end-to-end auto-venous graft was interposed under general anesthesia with anterior and posterior fasciotomy prior to blood flow restoration. Forced diuresis with a diuretic mixture and balanced fluid intake were used, and the patient was discharged from the intensive care unit on the 10th postoperative day in good condition with normal diuresis.

Insertion of intravascular stents into various arteries including coronary arteries has become an integral part of vascular interventions, particularly in the treatment of aortoiliac arteriosclerotic disease. The incidence of vascular complications remains relatively high despite the better stent design and inserting techniques. We report a case where successful removal of partially expanded Palmaz stent from external iliac artery was needed due to a rare complication: a balloon catheter burst resulting in an insufficient stent expansion in an improper position.

The presence of calcium in the vessel walls after end-to-end arterial anastomoses performed with polydioxanone and polypropylene interrupted sutures was studied in 140 anastomoses in 35 10-week-old German shepherd dogs. Histologic examination with hematoxylin and eosin, van Gieson, and von Kossa staining techniques was performed after the animals were killed 6 months after the operation. Ketamine hydrochloride was used as an anesthetic agent. At the start of the investigation the dogs weighed 14.5 +/- 2.6 kg (mean +/- standard deviation, n = 35), and after 6 months they weighed 45.3 +/- 3.1 kg (mean +/- standard deviation, n = 35). The diameter of the sutured arteries in the first operation was 2.6 +/- 0.5 mm (mean +/- standard deviation, n = 140). With each dog, both brachial and both femoral arteries were used--one artery for each different type of suture. In different dogs, different arteries were used for the same type of suture. The prevalence of calcifications after 6 months was determined from the numeric density of calcifications with standard stereologic techniques. The sutured and sutureless parts taken from longitudinal sections from each artery were studied, and t test values were calculated as follows: In paired samples, statistically significant differences in numerical density of calcifications were seen between sutured and sutureless arterial parts for both materials (sutureless part versus part with polydioxanone sutures, p < 0.001, n = 70; sutureless part versus part sutured with polypropylene sutures, p < 0.01, n = 70); however, in independent samples no statistically significant differences in numerical density of calcifications were seen between the polydioxanone and polypropylene groups for sutured (p > 0.05, n = 70) and sutureless parts (p > 0.05, n = 70).

Five dogs, 10 weeks old, underwent operation using ketamin-HCl anesthesia and end-to-end anastomoses of the femoral and brachial arteries were made using polyfilament nonabsorbable material (Ethibond), monofilament nonabsorbable material (Prolene), polyfilament absorbable material (Vicryl) and monofilament absorbable material (PDS). The arterial diameter using a micrometer and blood flow using an electromagnetic flow meter were determined. After six months another operation was performed and diameter and blood flow were measured again. No statistically significant differences were found between the different materials used with respect to growth related increases either in arterial diameter or blood flow.