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Significant Stenosis (significant + stenosis)
Selected AbstractsLobectomy for Pulmonary Vein Occlusion Secondary to Radiofrequency AblationJOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 9 2010MATTHEW A. STELIGA M.D. Pulmonary Vein Occlusion After RF Ablation., Pulmonary vein stenosis, a recognized complication of transcatheter radiofrequency ablation in the left atrium, is often asymptomatic. Significant stenosis is commonly treated with percutaneous balloon dilation with or without stenting. We encountered a case of complete pulmonary vein occlusion that caused lobar thrombosis, pleuritic pain, and persistent cough. Imaging studies revealed virtually no perfusion to the affected lobe. A lobectomy was performed, resolving the persistent cough and pain. Pulmonary vein occlusion should be suspected in patients who present with pulmonary symptoms after having undergone ablative procedures for atrial fibrillation. This condition may necessitate surgical intervention if interventions such as balloon dilation or stenting are not possible or are ineffective.,(J Cardiovasc Electrophysiol, Vol. 21, pp. 1055-1058, September 2010) [source] Noninvasive Coronary Flow Velocity Reserve Measurement in the Posterior Descending Coronary Artery for Detecting Coronary Stenosis in the Right Coronary Artery Using Contrast-Enhanced Transthoracic Doppler EchocardiographyECHOCARDIOGRAPHY, Issue 3 2004Hiroyuki Watanabe M.D. Background: Coronary flow velocity reserve (CFVR) measurement by transthoracic Doppler echocardiography (TTDE) has been found to be useful for assessing left anterior descending coronary artery (LAD) stenosis. However, this method has been restricted only for the LAD. The purpose of this study was to detect severe right coronary artery (RCA) stenosis by CFVR measurement using contrast-enhanced TTDE. Methods: In 60 consecutive patients with angina pectoris (mean (SD) age: 60 (11), 18 women), coronary flow velocities in the RCA were recorded in the postero-descending coronary artery by contrast-enhanced TTDE at rest and during hyperemia induced by intravenous infusion of adenosine triphosphate (140 mcg/ml/kg). CFVR was calculated as the ratio of hyperemic to basal peak and mean diastolic flow velocity. CFVR measurements by TTDE were compared with the results of coronary angiography performed within 1 week. Results: Coronary flow velocity was successfully recorded in 49 (82%) of the 60 patients with contrast agent. CFVR (mean (SD)) was 1.4 (0.4) in patients with, and 2.6 (0.6) in patients without significant stenosis in the RCA (%diameter stenosis > 75%, P < 0.001). Using the cutoff value 2.0 for CFVR in the RCA, its sensitivity and specificity in detecting significant stenosis in the RCA were 88% and 91%, respectively. Conclusion: CFVR measurement in the postero-descending coronary artery by contrast enhanced TTDE is a new, noninvasive method to detect significant stenosis in the RCA. (ECHOCARDIOGRAPHY, Volume 21, April 2004) [source] Noninvasive Assessment of Significant Right Coronary Artery Stenosis Based on Coronary Flow Velocity Reserve in the Right Coronary Artery by Transthoracic Doppler EchocardiographyECHOCARDIOGRAPHY, Issue 6 2003M.D., Yoshiki Ueno Background: Coronary flow velocity reserve (CFVR) measured by transthoracic Doppler echocardiography (TTDE) has been reported to be useful for the noninvasive assessment of coronary stenosis in the left anterior descending artery. However, the measurement of CFVR in the right coronary artery by TTDE has not yet been validated in a clinical study. Objective: The aim of this study was to evaluate whether CFVR by TTDE can detect significant stenosis in the right coronary artery. Methods: We studied 50 patients who underwent coronary angiography. Coronary flow velocity in the posterior descending branch of the right coronary artery (PD) was measured by TTDE both at baseline and during hyperemia induced by the intravenous infusion of adenosine triphosphate. CFVR was calculated as the hyperemia/baseline (average diastolic peak velocity). Results: Adequate spectral Doppler recordings in the PD were obtained in 36 patients including 26 patients who were given an echocardiographic contrast agent to improve Doppler spectral signals. The study population was divided into 2 groups with (Group A;n = 11) and without (Group B;n = 25) significant stenosis in the right coronary artery. CFVR in Group A was significantly smaller than that in Group B (1.6±0.3versus2.5±0.4; P < 0.0001). The sensitivity of a CFVR of <2.0 for predicting the presence of significant stenosis in the right coronary artery was 91%, and the specificity was 88%. Conclusions: The measurement of CFVR in the PD by TTDE is useful for the noninvasive assessment of significant stenosis in the right coronary artery. (ECHOCARDIOGRAPHY, Volume 20, August 2003) [source] Validation of Three-Dimensional Cardiac Image Integration: Use of Integrated CT Image into Electroanatomic Mapping System to Perform Catheter Ablation of Atrial FibrillationJOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 4 2006PETER M. KISTLER M.B.B.S., Ph.D. Introduction: Accurate visualization of the complex left atrial (LA) anatomy and the location of an ablation catheter within the chamber is important in the success and safety of ablation for atrial fibrillation (AF). We describe the integration of CT into an electroanatomic mapping (EAM) system and its validation in patients undergoing catheter ablation for AF. Methods and Results: Thirty patients (59.2 ± 8 years, 25 M) with paroxysmal (12) and persistent (18) AF underwent ablation using CT image integration into an electroanatomic mapping system. CT registration using the pulmonary veins as markers (landmark) was achieved with an error of 6.4 ± 2.8 mm with repeat registration required in two patients. Registration of the CT by best fit to a electroanatomic geometry (surface) was achieved with an error of 2.3 ± 0.4 mm. There was no significant difference in the regional LA registration error at superior (1.7 ± 0.7 mm), inferior (2.2 ± 1.4 mm), septal (1.7 ± 0.8 mm), and lateral (1.7 ± 0.7 mm, P = 0.13) sites. Cardiac rhythm at the time of CT did not have a significant effect on total or regional surface registration accuracy (mean total 2.5 ± 0.3 in AF patients vs 2.3 ± 0.5 in SR patients, P = 0.22). The integrated CT was used to guide the encirclement of the pulmonary veins (PV) in pairs with electrical isolation achieved by maintaining ablation along the ablation line in 58 of 60 PV pairs. Postprocedural PV angiography did not demonstrate significant stenosis. Conclusion: CT image integration into an EAM system was successfully performed in patients undergoing catheter ablation for AF. With a greater appreciation of the complex and variable nature of the PV and LA anatomy this new technology may improve the efficacy and safety of the procedure. [source] Duplex Doppler sonography of transplant renal artery stenosisJOURNAL OF CLINICAL ULTRASOUND, Issue 3 2003Ruth Helena de Morais MD Abstract Purpose The aim of this study was to evaluate the accuracy of duplex Doppler sonography in diagnosing transplant renal artery stenosis (TRAS) and to determine which parameter is the most reliable for making that diagnosis. Methods Over a 3-year period, we sonographically evaluated patients who were referred for investigation of possible TRAS. We investigated the following parameters: peak systolic velocity (PSV) in the external iliac and renal arteries, acceleration time and acceleration in the intrarenal arteries, acceleration time in the renal artery, resistance index, and the ratio of the PSVs in the renal and external iliac arteries. We also used MR angiography and digital subtraction arteriography to verify the degree of stenosis. After the evaluations, the patients were classified into 2 groups, 1 with and the other without significant stenosis (> 50% narrowing of the lumen) on digital subtraction arteriography. We also included a control group of patients who had undergone renal transplantation at least 6 months before, had had a good course after transplantation, had a diastolic blood pressure of 90 mm Hg or less, and were taking a maximum of 1 antihypertensive drug. Results Our study population consisted of 22 patients suspected to have TRAS (10 without and 12 with confirmed significant stenosis) and 19 control patients. We found statistically significant differences between the mean values of these 3 groups except for the PSV in the iliac artery and the resistance index in the intrarenal arteries. The most accurate parameters to use in diagnosing TRAS were an acceleration time of 0.1 second or higher in the renal and intrarenal arteries, a PSV of greater than 200 cm/second in the renal artery, and a ratio of PSVs in the renal and external iliac arteries of greater than 1.8. Conclusions Duplex Doppler sonography is an excellent method for screening patients suspected to have TRAS and can help select which of those patients should undergo digital subtraction arteriography. © 2003 Wiley Periodicals, Inc. J Clin Ultrasound 31:135,141, 2003 [source] Predicting vascular access failure: A collective reviewNEPHROLOGY, Issue 4 2002Kevan R POLKINGHORNE SUMMARY: The maintenance of vascular access for haemodialysis contributes a large burden of morbidity and cost to any dialysis unit. Identifying vascular access at risk of thrombosis is an evolving and important aspect to the management of any haemodialysis patient. Haemodynamic profiles of native fistulas and arteriovenous grafts differ significantly, and, as such, the sensitivity of the specific monitoring techniques to detect dysfunction varies depending on access type. Multiple strategies are now available for monitoring vascular access including measuring intra-access pressure and access blood flow, or screening for significant stenoses with Doppler ultrasonography. the ability of each strategy to detect significant stenosis is reviewed by looking at the evidence for both arteriovenous fistula (AVF) and arteriovenous grafts (AVG), separately. the majority of published literature involves AVG, and measuring access blood flow is the modality of choice. the best method for measuring flow is not known. For AVF, much less is known, and it is not clear whether monitoring will decrease the thrombosis risk and prolong access life. Recommendations for AVF cannot be made until more evidence becomes available. [source] Stridor is not a scientifically valid outcome measure for assessing airway injuryPEDIATRIC ANESTHESIA, Issue 2009JOSEF HOLZKI MD Summary Since about a decade cuffed intubation is becoming more popular in pediatric anesthesia. Studies supporting cuffed intubation compared cuffed and uncuffed intubation by using stridor as main outcome measure after extubation. No differentiations were made between benign (oedema) and severe (ulceration of mucosa) lesions. Stridor was considered to represent all relevant injuries. Far reaching conclusions for daily practice were drawn from these studies. Pediatric endoscopists and , ENT-surgeons with extensive experience in this field have warned against this opinion because significant injury of the airway is not always accompanied by stridor! The symptom of stridor might develop weeks and months after injury when silent ulcerations of the mucosa retract to significant stenosis. Only endoscopy can evidently detect all airway injuries. Studies describing airway injury by endoscopic control are urgently needed to find the best way of preventing airway injury by intubation. [source] Diagnostic Significance of a Small Q Wave in Precordial Leads V2 or V3ANNALS OF NONINVASIVE ELECTROCARDIOLOGY, Issue 2 2010Tetsuya Katsuno M.D. Background: An abnormal Q wave is usually defined as an initial depression of the QRS complex having a duration of ,40 ms and amplitude exceeding 25% of the following R wave in any contiguous leads on the 12-lead electrocardiogram (ECG). However, much smaller Q waves are sometimes recorded on the ECG. This study investigated the diagnostic value of the small Q wave recorded in precordial leads V2 or V3 on the ECG. Methods: We investigated 807 consecutive patients who underwent coronary angiography. A small Q wave was defined as any negative deflection preceding the R wave in V2 or V3 with <40-ms duration and <0.5-mV amplitude, with or without a small (<0.1-mV) slurred, spiky fragmented initial QRS deflection before the Q wave (early fragmentation). ECG and coronary angiographic findings were analyzed. Results: The small Q wave was present in 87 patients. Multiple logistic regression analysis revealed that presence of a small Q wave was a strong independent predictor of any coronary artery stenosis or left anterior descending artery (LAD) stenosis (odds ratio = 2.706, 2.902; P < 0.001, < 0.001, respectively). Conclusion: A small Q wave (<40-ms duration and <0.5-mV amplitude) in V2 or V3 with or without early fragmentation significantly predicted the presence of CAD and, especially, significant stenosis in the LAD. Ann Noninvasive Electrocardiol 2010;15(2):116,123 [source] Percutaneous intervention for chronic total occlusion of the internal iliac artery for unrelenting buttock claudication,CATHETERIZATION AND CARDIOVASCULAR INTERVENTIONS, Issue 2 2009Satjit Adlakha DO Abstract Internal iliac artery stenosis or occlusion has been documented to cause hip pain, erectile dysfunction, and buttock claudication. Endovascular repair for patients with significant stenosis has been well documented, but chronic total occlusion revascularizations have not been reported in the literature. The reluctance to attempt percutaneous intervention may be in part due to the extensive collateralization that forms to this vessel, or fear of complications such as wire perforation in a vessel that has a tortuous route with multiple bifurcations. This report describes two cases of patients with unrelenting buttock claudication that completely resolved after percutaneous intervention of unilateral chronic total occlusions of the internal iliac artery. © 2008 Wiley-Liss, Inc. [source] | ||||||||||