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K Skarvan

Publications and source records attributed to K Skarvan.

At least 19 recordsLinked to original sources
PubMed1997

The inverse Nehb J lead increases the sensitivity of Holter electrocardiographic monitoring for detecting myocardial ischemia.

A major reason for the relatively low sensitivity of Holter electrocardiography (ECG) for detecting ischemia is that the sensitivity of bipolar leads used for Holter ischemia monitoring has not been systematically evaluated, making lead selection difficult. Therefore, this study evaluated the sensitivity of 6 bipolar Holter leads for detecting ischemia during percutaneous transluminal coronary angioplasty. Seventy-five patients, each of whom had > 1 mm ST-segment elevation on an intracoronary electrocardiogram from the myocardium distal to the stenosis during balloon occlusion, were studied for the occurrence of > or = 1 mm ST-segment elevation or depression on the simultaneously recorded Holter leads II, III, aVF, CM5, CR4, and inverse Nehb J. The study found that the inverse lead Nehb J provided a significantly higher overall sensitivity for detecting myocardial ischemia than Holter leads II, III, aVF, CM5, and CR4. Also, the use of inverse lead Nehb J significantly increased the sensitivity of 2- and 3-lead Holter ischemia monitoring. These findings were based on a significantly higher sensitivity of inverse lead Nehb J for detecting ischemia induced by transient occlusion of the left anterior descending coronary artery and a slightly higher sensitivity for detecting ischemia induced by occlusion of the left circumflex coronary artery. None of the bipolar leads studied provided a very high sensitivity for detecting ischemia induced by occlusion of the right coronary artery. These findings show that adequate lead selection can increase the sensitivity of Holter ischemia monitoring. Furthermore, the lack of a highly sensitive lead for detection of inferior ischemia indicates that further evaluation of bipolar leads is warranted.

Angioplasty, Balloon, Coronary↗
PubMed1997

[Long-term electrocardiography. Detection of low-grade myocardial infarction: sensitivity of 9 bipolar leads].

UNLABELLED: The sensitivity of ambulatory electrocardiography (Holter ECG) for detecting ischaemia is relatively low. A case report of an inferior infarction missed by three-lead Holter monitoring that included a modified lead aVF especially places its sensitivity for detecting inferior ischaemia and infarction in question. Therefore, the present study evaluated the sensitivity of nine bipolar Holter leads for detecting isolated inferior Q-wave infarctions, and compared the sensitivity of the modified leads II, III, and aVF of the Holter ECG with the sensitivity of the "corresponding" leads of the standard ECG. METHODS: Sixteen patients, each of whom had a pathological Q-wave (> 0.04 s and > 0.1 mV) in at least two of the three standard ECG leads II, III, and aVF but in none of the other standard leads, were studied for the presence of a pathological Q-wave on the modified Holter leads II, III, aVF, CM2, CM5, CR4, Frank Z, Nehb D, and inverse Nehb J. RESULTS: Of the nine Holter leads, modified lead III provided the highest sensitivity for detecting inferior Q-wave infarctions, followed by lead Frank Z; leads CR 4 and inverse Nehb J were only slightly less sensitive. In contrast, modified leads II and aVF were significantly less sensitive than modified lead III. Modified bipolar lead aVF of the Holter ECG was significantly less sensitive than the "corresponding" lead aVF of the standard ECG, whereas modified leads II and III provided similar sensitivities for detecting inferior Q-wave infarctions as the "corresponding" leads of the standard ECG. CONCLUSIONS: The significantly lower sensitivity of modified lead aVF for detecting inferior Q-wave infarctions compared with standard lead aVF shows that the sensitivity of a Holter ECG lead cannot be deduced from that of the "corresponding" standard ECG lead. Moreover, the significantly higher sensitivity of modified lead III compared with modified leads II and aVF shows that lead selection is important for Holter monitoring.

Aged↗
PubMed1997

Occlusive mesenteric ischemia and its effects on jejunal intramucosal pH, mesenteric oxygen consumption and oxygen tensions from surfaces of the jejunum in anesthetized pigs.

OBJECTIVE: To investigate the effects of superior mesenteric artery (SMA) flow reduction on the jejunal intramucosal pH (pHi) and to compare these effects with corresponding changes of mesenteric oxygen transport variables and oxygen tensions on the surfaces of the jejunal serosa and mucosa. DESIGN: Prospective, randomized, controlled, experimental study. SETTING: Animal research laboratory. SUBJECTS: 20 domestic pigs. INTERVENTIONS: Mechanical flow reduction in the SMA. The animals were randomized to have an SMA flow of 0%, 25%, 38%, 50% or 100% (control). MEASUREMENTS AND MAIN RESULTS: Measurements (baseline, ischemia, reperfusion) consisted of hemodynamic and oxygen transport variables, SMA blood flow, mesenteric oxygen transport variables, pHi and oxygen tensions of the jejunal serosa and mucosa. Flow reduction in the SMA resulted in a significant decrease of pHi indicating ischemia earlier than mesenteric oxygen transport variables. The relationship between mesenteric oxygen delivery (DO2ms) and pHi during acute ischemia is best described by a sigmoid curve. There was a linear correlation between the changes of the jejunal surface oxygen tensions and pHi due to SMA flow reduction. CONCLUSION: The sigmoid relationship between pHi and DO2ms indicated that pHi is a sensitive parameter for detecting ischemia at 50% of the baseline oxygen delivery and that below 25% there was no further decrease of pHi. In contrast, mesenteric and whole body oxygen transport parameters were not indicative of impaired mucosal oxygen supply.

Analysis of Variance↗
PubMed1997

Prevention of supraventricular tachyarrhythmias after open heart operation by low-dose sotalol: a prospective, double-blind, randomized, placebo-controlled study.

BACKGROUND: The aim of this prospective, double-blind, placebo-controlled trial was to assess the preventive effect and safety of low-dose sotalol after heart operation. METHODS: Two hundred fifty-five consecutive patients referred for elective coronary artery bypass grafting (n = 220) or aortic valve operation (n = 35) were randomized to receive either 80 mg of sotalol twice daily (n = 126) or matching placebo (n = 129) for 3 months, with the first dose given 2 hours before operation. RESULTS: There were no significant baseline differences between the groups. Overall, supraventricular tachyarrhythmias occurred in 36% of patients (82% atrial fibrillation). Hospital stay was 11.6 +/- 5 days in patients with supraventricular arrhythmias, versus 9.5 +/- 2.4 days in patients without it (p < 0.0001). Low-dose sotalol reduced the rate of supraventricular arrhythmias from 46% (placebo) to 26% (sotalol; p = 0.0012), or by 43%. On the fourth postoperative day, heart rate was lower in the sotalol group (74 +/- 12 beats/min versus 85 +/- 15 beats/min; p < 0.0001) but the QT interval corrected for the heart rate was not prolonged (sotalol group, 0.44 +/- 0.03 second; placebo group, 0.43 +/- 0.03 second; p = not significant). Study medication had to be discontinued because of side effects in 5.6% of sotalol and 3.9% of placebo patients (p = not significant), with one possible proarrhythmic event occurring in a patient receiving sotalol. CONCLUSIONS: Because more than 90% of supraventricular arrhythmic episodes occurred within 9 days after operation and 70% of all possibly sotalol related side effects occurred after day 9, the findings in this study imply that prophylactic treatment with sotalol may be limited to the first 9 postoperative days.

Aged↗
PubMed1995

Exercise capacity as a predictor of postoperative complications in lung resection candidates.

Exercise testing with measurement of maximal oxygen uptake (VO2max) is increasingly used in the assessment of lung resection candidates, but its predictive value for postoperative complications remains controversial. We therefore sought to determine the prognostic value of VO2max compared with other pulmonary function tests. A consecutive group of 80 patients (mean age 61 yr; 57 males and 23 females) scheduled for lung resection (62 malignancies, 12 benign disorders, and 6 carcinoids) underwent pulmonary function tests and symptom-limited cycle ergometry. All patients underwent lung resections: 21 pneumonectomies, 45 lobectomies, and 14 segmental or wedge resections. Group A (64 patients, 80%) had an uneventful postoperative course, whereas Group B (16 patients, 20%) had complications; 3 of them died (4% overall mortality rate). In a stepwise logistic regression analysis used to determine independent risk factors for postoperative complications (within 30 d), VO2max expressed as a percentage of predicted (84 +/- 19 for Group A versus 61 +/- 11 for Group B) proved to be the best predictor (predictive value 85.5%). Although VO2max expressed in absolute values (ml/kg/min) was also highly predictive (79.5%), a ROC curve analysis proved the percentage predicted values to be significantly more sensitive. Of 9 patients with a VO2max < 60% of predicted, 8 had complications, including all 3 patients who died after resections of more than one lobe (sensitivity 50%, specificity 98%). The estimated probability (probit model SAS software package) of suffering no complication was 0.9 for VO2max > 75% of predicted and 0.1 for a VO2max < 43%.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

[Massive intraoperative pulmonary embolism. Diagnosis and control following embolectomy with transesophageal echocardiography].

Massive intraoperative embolism is a life-threatening condition that may lead to immediate death. Important for the survival of the patient are rapid diagnosis and prompt surgical embolectomy. Case report. Nineteen days after a traffic accident, a 67-year-old patient who had complex ligamentous injuries was operated upon on both knees during general anaesthesia. The operation progressed uneventfully for the first 30 min when the patient's systolic blood pressure became slightly unstable and decreased to 85 mm Hg despite administration of ephedrine and infusion of hetastarch. This was followed 30 min later by an immediate drop to values that were undetectable on an oscilloscope. The pulse oximeter no longer detected a signal at the finger-tip and the end-tidal CO2 decreased to 1 kPa (7.5 mm Hg). To confirm the diagnosis of an acute pulmonary embolism, we performed transoesophageal echocardiography (TEE) and found a large amount of free-floating material in the right atrium, a dilated and hypokinetic right ventricle, and a collapsed left ventricle (Fig. 1 a). Embolectomy was immediately started using the inflow-occlusion technique supported by cardiopulmonary bypass (CPB). All emboli were removed from the right atrium and pulmonary artery (Fig. 1 b). During closure of the sternotomy, heart function was monitored by TEE and we again noted large emboli in the right atrium (Fig. 1 c). To remove these, we reinstated CPB and then placed an inferior vena cava filter. The final TEE control showed free heart chambers with good contractility (Fig. 1 d).(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1994

Spinal anaesthesia in a patient with Takayasu's disease.

We report the successful anaesthetic management of therapeutic abortion under spinal anaesthesia in a 32-yr-old woman with Takayasu's disease. The pathology and pathophysiology of this syndrome and their impact on anaesthesia are discussed.

Abortion, Therapeutic↗
PubMed1994

Prolonged decrease in heart rate variability after elective hip arthroplasty.

The pattern of postoperative heart rate variability may provide insight into the response of the autonomic nervous system to anaesthesia and surgery. We have obtained spectral (fast Fourier transform) and non-spectral indices of heart rate variability from electrocardiographic recordings, sampled during continuous perioperative Holter monitoring in 15 otherwise healthy patients with an uncomplicated postoperative course, undergoing elective hip arthroplasty with either spinal or general anaesthesia. In both groups, total spectral energy (0.01-1 Hz), low-frequency spectral energy (0.01-0.15 Hz) and high-frequency spectral energy (0.15-0.40 Hz) decreased after surgery to 32% (95% confidence interval (CI) 10.5; P < 0.01), 29% (95% CI 12.5; P < 0.01) and 33% (95% CI 12.5; P < 0.01) of their preoperative values, respectively, and these indices remained suppressed for up to 5 days. Non-spectral indices decreased to a similar extent. These findings indicate a substantial and prolonged postoperative decrease in both parasympathetic and sympathetic influence on the sinus node.

Aged↗
PubMed1993

[Perioperative transesophageal echocardiography in heart surgery].

Transesophageal echocardiography (TEE) has proven to be a safe and useful method in open heart surgery. TEE allows the anesthesiologist to monitor global and regional ventricular function continuously and to optimize hemodynamic management. It offers the cardiac surgeon additional information and more safety with regard to planning and conduct of surgery as well as the possibility of immediate assessment of the surgical result. Correctly applied, TEE improves the overall quality of perioperative patient care.

Anesthesia↗
PubMed1993

[Transesophageal echocardiography for evaluating left ventricular function].

By means of transesophageal echocardiography it is now possible to assess and to monitor left ventricular function during anesthesia and surgery. Furthermore, the determinants of the left ventricular function (preload, afterload and contractility) can also be evaluated in real time. Based on this information, a specific therapy can be started immediately should ventricular function become inadequate. In addition to global function, regional ventricular function can be analyzed at the same time. The detection of regional wall motion abnormalities can be most helpful for anesthetic management of patients with coronary heart disease and for the diagnosis of intraoperative myocardial ischemia.

Anesthesia Recovery Period↗
PubMed1992

Perioperative myocardial ischemia in patients undergoing elective hip arthroplasty during lumbar regional anesthesia.

Perioperative myocardial ischemia predicts unfavorable outcomes and occurs in as many as 41% of patients with coronary artery disease or cardiac risk factors undergoing noncardiac surgery. To determine the prevalence of myocardial ischemia, we studied 52 consecutive unselected patients undergoing elective hip arthroplasty during lumbar regional anesthesia. Patients were continuously monitored for 6 days using a three-channel Holter monitor. Ninety-nine episodes of myocardial ischemia occurred in 16 patients (31%), six of whom were considered preoperatively to be at low risk for coronary artery disease. Forty-four percent of the ischemic episodes were preceded or accompanied by a heart rate greater than or equal to 100/min and 56% by a heart rate greater than or equal to 90 beats/min. Ninety-six percent of the ischemic episodes were clinically silent, and 82% were not related to patient care events. Thirteen episodes of myocardial ischemia occurred preoperatively, 1 intraoperatively, and 85 postoperatively. The incidence of postoperative ischemic episodes showed a circadian variation: 44% occurred between 6 AM and noon, 33% between noon and 6 PM, 17% between 6 PM and midnight, and 6% between midnight and 6 AM. Six adverse cardiac events occurred during hospitalization (three of the six among patients with perioperative ischemia) and an additional four events during a follow-up period of 12 months (all four events occurred among patients with perioperative ischemia). Patients with perioperative myocardial ischemia had a relative risk of 2.6 (95% confidence interval 1.3-5.2) to develop an adverse cardiac event postoperatively.

Aged↗
PubMed1992

Failure of continuous three-channel Holter monitoring to detect acute peri-operative myocardial infarction.

Continuous peri-operative three-channel Holter monitoring in a 70-year-old patient undergoing elective hip arthroplasty failed to show onset and progression of a lethal postoperative myocardial infarction, which was clearly visible in a 12-lead electrocardiogram. The modified bipolar leads used for Holter monitoring differed from the corresponding leads of the 12-lead electrocardiogram. The limitations of Holter monitoring applied to clinical management and research are highlighted.

Aged↗
PubMed1990

[Transesophageal echocardiography].

Transesophageal echocardiography is a new, semi-invasive technique for the examination of the heart and the aorta. Within 10-15 minutes it is possible to obtain good pictures of the anatomy and function of the heart. Diagnostic indications are native and prosthetic valvular heart disease; the method is particularly suitable for visualization of endocarditic vegetations, evaluation of embolic events or congenital heart disease and assessment of aortic dissection. In the intensive care unit transesophageal echocardiography is a new window to the heart, yielding instantaneous information on cardiac status. For the anesthetist it is the first method to provide perioperative beat to beat analysis of ventricular function.

Aortic Dissection↗
PubMed1990

Prevention of aortocoronary vein bypass graft occlusion: which antithrombotic treatment and for how long?

The effects of 50 mg aspirin combined with 400 mg dipyridamole were compared with those of standard anticoagulant therapy, in the prevention of aortocoronary vein bypass graft occlusion. Early graft occlusion in 249 patients, with 749 distal vein graft anastomoses, were angiographically assessed 11.5 +/- 2 days after surgery and were almost equal in both treatment groups. In half of the patients in each group, active treatment was replaced by placebo after 3 months. Repeat angiography after 1 year (360 +/- 24 days) showed that more new late graft occlusions occurred in patients with only 3 months active medication (either regimen). The incidence of major complications was significantly higher in patients treated with anticoagulants, with minor side-effects more common in the antiplatelet group. Thus, this antiplatelet drug regimen was as effective as standard anticoagulant therapy in the prevention of early and late bypass graft occlusion, but carried a significantly lower risk of severe complications. In addition, as replacement of active treatment by placebo after 3 months resulted in significantly more graft occlusions, antithrombotic treatment should be continued for at least one year after coronary artery bypass graft surgery.

Adult↗
PubMed1990

[Diagnostic value of CK-MB for the determination of perioperative infarct in coronary artery bypass operation].

To assess the diagnostic value of CK-MB determinations after CABG surgery to detect or exclude perioperative myocardial infarction, 228 consecutive patients were studied with serial ECGs, as well as pre- and postoperative left heart catheterization and thallium-201-scintigraphy. CK-MB values above or below 100 U/l had a sensitivity and specificity of 73% each. There was a linear correlation between CK-MB values and total ischemic time. Thus, an increasing amount of myocardium is lost with each additional minute of ischemia despite today's methods of myocardial protection. Due to its low diagnostic accuracy CK-MB seems not to be very helpful for the diagnosis of perioperative myocardial infarction.

Adult↗