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G Stix

Publications and source records attributed to G Stix.

At least 19 recordsLinked to original sources
PubMed1998

Comparison of transesophageal Doppler coronary flow reserve measurements with thallium-201 single-photon emission computed tomography imaging in assessment of left anterior descending artery stenoses.

BACKGROUND AND HYPOTHESIS: Recent studies demonstrate the feasibility of coronary flow reserve measurements by transesophageal echocardiographic (TEE) Doppler recordings of coronary sinus or left anterior descending (LAD) coronary artery flow velocity for detecting stenoses of the LAD artery. This study compares coronary flow reserve measurements by Doppler TEE with thallium-201 (201Tl) single-photon emission computed tomography (SPECT) in patients with proximal single-vessel LAD stenosis. METHODS: Nineteen patients with various degrees of LAD stenosis (mean area stenosis 71 +/- 24%; range 24-96%) were studied. Area stenosis by quantitative coronary angiography was < 75% in 7 patients and > 75% in 12 patients. Transesophageal LAD and coronary sinus Doppler measurements were performed at baseline and after intravenous dipyridamole. Coronary flow reserve was calculated as the ratio of hyperemic to baseline average peak velocities. Predefined coronary flow reserve cut-off values of 1.8 for the coronary sinus method and of 2.0 for the LAD method were used for diagnosis of significant LAD stenosis. Results were compared with qualitative 201Tl dipyridamole SPECT. RESULTS: Overall predictive accuracy for diagnosis of > 75% LAD stenosis was 79% for 201Tl SPECT, 77% for the transesophageal LAD and 79% for the transesophageal coronary sinus technique. Concordant results between 201Tl SPECT and the LAD and coronary sinus Doppler methods were observed in 79% and 71% of patients, respectively. CONCLUSIONS: Thallium-201 SPECT and transesophageal Doppler assessment of coronary flow reserve have similar accuracy for diagnosing significant proximal LAD stenosis. Therefore, both transesophageal Doppler techniques might constitute another widely available, noninvasive method for assessment of left coronary artery disease, if disease location is proximal.

Blood Flow Velocity↗
PubMed1998

Transjugular intrahepatic portosystemic shunt and cardiac arrhythmias.

The approach to the liver for a transjugular intrahepatic porto-systemic shunt (TIPS) is through the venous system. Because catheter and guidewire system traverses the heart, cardiac arrhythmias may be expected during the procedure. We have prospectively investigated the incidence of such dysrhythmias during TIPS implantation. Twelve consecutive patients, 4 women and 8 men aged 26 to 75 years (mean, 58 +/- 13 years), were studied. Before and on the day of TIPS implantation, a 24-hour Holter recording was performed. Transjugular intrahepatic portosystemic shunt implantation was performed under local anesthesia (lidocaine) and sedoanalgesia (midazolam and fentanyl). None of the patients had concomitant cardiac disease or electrolyte disturbances. In all patients except one, TIPS implantation was successful without any technical complications. A mean of 43 +/- 5.3 hours of Holter recording was performed before and after TIPS implantation. All recordings obtained during this control period were considered inconspicuous. The mean heart rate was significantly higher during the implantation procedure of 136 +/- 37 minutes' duration (83 +/- 20 beats per minute vs 70 +/- 19 beats per minute; p < 0.01). Nine of the 12 patients experienced episodes of nonsustained supraventricular tachycardias, and one patient had two sustained supraventricular tachycardias. Frequent episodes of nonsustained ventricular tachycardias developed in 75% of the patients. It seems clear that TIPS implantation is frequently associated with supraventricular and ventricular tachyarrhythmias even in patients with apparently good cardiac condition at the beginning of the procedure. Thus close cardiac monitoring with resuscitation equipment immediately available throughout the procedure is mandatory.

Adult↗
PubMed1997

Growing a new field.

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Biocompatible Materials↗
PubMed1996

Perioperative myocardial injury with different modes of antegrade and retrograde cardioplegic delivery.

The effect of three cardioplegic protocols on perioperative myocardial injury was studied in 62 coronary artery bypass grafting (CABG) patients randomized into three groups with either antegrade or retrograde cold blood cardioplegia, or coronary sinus occlusion during antegrade supply. During the aortic cross-clamp time anterior and posterior septal temperatures were recorded, indicating the distribution of cardioplegic solution within the myocardium. Serum creatine kinase (CK), CK-isoenzyme MB and myoglobin as well as 12-lead electrocardiograms (ECG) were analyzed. Statistical analysis showed no effect of the cardioplegic protocol, whereas the patient's preoperative status, aortic cross-clamp time and intraoperative myocardial temperature had significant (P < 0.05) effects on immediate postoperative CK and CK-MB enzyme release. Creatine kinase-MB peak values were significantly increased in patients with major vessel disease and reduced left ventricular function (92 +/- 53 U/l versus 67 +/- 25 U/l). Both CK and CK-MB values were significantly higher in patients with aortic cross-clamp times of more than 1 h than in patients with shorter clamping times (661 +/- 188 and 78 +/- 40 U/l versus 500 +/- 200 and 57 +/- 24 U/l). Patients with 22 +/- 3 degrees C myocardial temperature before terminal cardioplegia had significantly elevated CK as compared to patients with temperatures of 15 +/- 2 degrees C (665 +/- 185 U/l versus 510 +/- 211 U/l). However, enzyme peak values had only poor predictive power for postoperative ECG changes, suggesting that enzyme peaks were not necessarily a sign of perioperative ischemia. Patients with major vessel disease and reduced myocardial function, with aortic cross-clamp time of more than 1 h and/or inadequate intraoperative myocardial cooling may be highly susceptible to global ischemia and operative procedures, and therefore show elevated peak enzyme levels shortly after surgery. In contrast, elevated myoglobin peaks within 1 h after aortic declamping were significantly correlated to perioperative signs of transient ischemia (P < 0.02).

Aged↗
PubMed1996

Implantation of a unipolar cardioverter/defibrillator system under local anaesthesia.

OBJECTIVE: To evaluate prospectively the safety and feasibility of the implantation of cardioverter/defibrillator systems under local anaesthesia. Conventionally, cardioverter/defibrillator systems are implanted under general anaesthesia. With the development of single-lead transvenous unipolar cardioverter/defibrillator systems for subpectoral implantation a pacemaker-like approach for device implantation appears applicable. METHODS: Implantation of a single-lead transvenous unipolar cardioverter/defibrillator under local anaesthesia with sedation for defibrillation threshold testing was performed in 37 consecutive patients. The presenting arrhythmia was ventricular fibrillation in 13 patients, and monomorphic ventricular tachycardia in 24 patients. A 1% lidocaine solution was used for local anaesthesia, and midazolam was applied for sedation to perform defibrillation threshold testing. Arterial blood pressure, arterial oxygen saturation and heart rate were monitored throughout the procedure. The patient's tolerance of the implantation procedure was evaluated with a standardized questionnaire. RESULTS: The unipolar transvenous cardioverter/defibrillator system was implanted successfully in all patients under local anaesthesia. During defibrillation threshold testing, sufficient sedation was achieved with 12.5 +/- 3.7 mg midazolam. For determination of the defibrillation threshold 5.9 +/- 1.4 episodes of ventricular fibrillation were induced. The mean defibrillation threshold was 13.1 +/- 5.5 J, and the mean duration of the implantation procedure was 68 +/- 30 min. Mean heart rate, mean arterial blood pressure and arterial oxygen saturation were not significantly different before and after defibrillation threshold testing. Twenty-six patients (70%) were symptom-free throughout the implantation procedure; most of the remaining patients reported minor symptoms. There were no complications, and patients were discharged 2.2 +/- 0.7 days after implantation. In 12 patients, post-implant testing of the implantable cardioverter/defibrillators was performed successfully, without sedation, 2.8 +/- 1.4 days after as an outpatient procedure. CONCLUSION: Single-lead unipolar transvenous implantable cardioverter/defibrillator systems can be safely implanted under local anaesthesia with mild sedation for defibrillation threshold testing. The procedure is well tolerated.

Aged↗
PubMed1996

Comparison of three cardioverter defibrillator implantation techniques: initial results with transvenous pectoral implantation.

A total of 121 patients underwent epicardial (n = 32), transvenous abdominal (n = 30), and transvenous pectoral (n = 59) ICD implants. Perioperative complications were defined as those occurring within 30 days after surgery. Hospital costs were calculated with $750 per day as a fixed charge. Duration of surgery was the time between the first skin incision and the last skin suture. Severe perioperative complications that were life-threatening or required surgical intervention occurred in the epicardial (6%) and transvenous (10%) abdominal groups, but not in the pectoral group. Perioperative mortality occurred only in the epicardial abdominal group, predominantly in patients with concomitant surgery (18%), and in 5% of patients without concomitant surgery. The duration of surgery was significantly shorter for transvenous pectoral implantation (58 +/- 15 min, P < 0.05) compared to transvenous abdominal implantation (115 +/- 38 min). Epicardial abdominal ICD implantation had the longest procedure time (154 +/- 31 min). The postimplant hospital length of stay was significantly shorter for pectoral implantation (5 +/- 3 days, P < 0.05) compared to transvenous (13 +/- 5) and epicardial (19 +/- 5) abdominal implantation. Total hospitalization costs significantly decreased in the pectoral implantation group ($4,068 +/- $2,099 for the pectoral group vs $14,887 +/- $4,415 and $9,975 +/- $3,657 for the epicardial and the transvenous abdominal group, respectively, P < 0.05). These initial results demonstrate the advantage of transvenous pectoral ICD implantation in terms of perioperative complications, procedure time, hospital length of stay, and hospitalization costs.

Abdominal Muscles↗
PubMed1994

Results of percutaneous transseptal mitral commissurotomy in patients 40 years and above with those under 40 years of age: immediate and 5-year follow-up results.

Patients with mitral stenosis in Western countries are relatively old. It is anticipated that percutaneous transseptal mitral commissurotomy (PTMC) may have more complications and may not be as effective in this group of patient as in younger patients due to more calcification and fibrosis of the mitral valve. We analysed the clinical, hemodynamic, echocardiographic data in 296 consecutive patients divided prospectively into two groups; group 1 consisted of 184 patients > or = 40 years and group 2 of 112 patients < 40 years coming mostly from developing countries. The immediate gain in valve area was 2.18 +/- 0.61 cm2 in group 1 vs. 2.31 +/- 0.65 cm2 in group 2 (P = ns). The incidence of acute regurgitation requiring surgical intervention was similar in both groups. Follow-up data up to 5 years after PTMC was available in 170 patients (92.4%) in group 1 (mean 20 +/- 13 months) and 83 patients (74.1%) in group 2 (mean 29 +/- 17 months). Restenosis by Doppler method (valve area less than 1.5 cm2 with loss of at least 50% initial gain in valve area) was found in 33 patients in group 1 (29.2%) vs. 11 (14.9%) in group 2 (P < 0.05). Events free from death, need for mitral valve replacement or repeat PTMC at 5 year follow-up was 76% in group 1 vs. 87% in group 2 (P < 0.05). We conclude that the immediate effectiveness and acute complications of PTMC in patients 40 years and above are comparable to younger patients. Restenosis is clearly higher and there is a trend towards need for mitral valve replacement in patients 40 years and above at follow-up. However, the continuing benefit for the majority of the patients 40 years and above (76% free from adverse events) would suggest that PTMC is an appropriate treatment modality even in the older patients.

Adult↗
PubMed1994

Power medicine.

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Administration, Cutaneous↗