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Biomedical subjects

Christian Seiler

Publications and source records attributed to Christian Seiler.

41 records · Page 3Linked to original sources
PubMed2002

Physiologically assessed coronary collateral flow and adverse cardiac ischemic events: a follow-up study in 403 patients with coronary artery disease.

OBJECTIVES: We sought to evaluate whether coronary collateral flow is clinically relevant for future cardiac ischemic events. BACKGROUND: The link between good collateral supply related to less myocardial damage and fewer cardiac events has not been established prospectively beyond doubt. METHODS: In 403 patients with stable angina pectoris undergoing percutaneous transluminal coronary angioplasty (PTCA) and quantitative collateral assessment, the occurrence of major adverse cardiac events ([MACE] cardiac death, myocardial infarction, unstable angina pectoris) and stable angina pectoris was monitored during follow-up. Collateral flow index (CFI) was determined using intracoronary pressure or Doppler guidewires. Mean aortic ([P(ao)] mm Hg) and distal coronary artery occlusive pressure ([P(occl)] mm Hg) during balloon angioplasty (PTCA), or distal coronary flow velocity time integral during ([V(occl)] cm) and after ([V(ø-occl)] cm) PTCA were measured continuously. Pressure-derived CFI was calculated as follows: (P(occl) - 5)/(P(ao) - 5). Doppler-derived CFI: V(occl)/V(ø-occl). Patients were subdivided into a group with well (CFI > or = 0.25) and poorly developed collaterals (CFI < 0.25). RESULTS: Average follow-up was 94 +/- 56 (15 to 202) weeks. There were 134 patients with CFI >or =0.25 (61 +/- 11 years) and 269 with CFI <0.25 (61 +/- 10 years). The overall cardiac ischemic event rate (MACE and stable angina pectoris) during follow-up was 23% in patients with CFI > or =0.25 and 20% in patients with CFI <0.25 (p = NS). However, only 2.2% of patients with good collateral flow suffered a major cardiac ischemic event, compared with 9.0% among patients with poorly developed collaterals (p = 0.01). The incidence of stable angina pectoris was significantly higher in patients with well developed collaterals than in those with poorly developed collaterals (21% vs. 12%; p = 0.01). CONCLUSIONS: In this relatively large population with chronic stable coronary artery disease undergoing quantitative collateral measurement, the beneficial impact of well developed collateral vessels on the occurrence of future major cardiac ischemic events is clearly demonstrated.

Aged↗
PubMed2002

Validation of six noninvasive Doppler methods for the assessment of left ventricular filling pressure.

OBJECTIVES: The aim of this study was to determine the accuracy of six noninvasive Doppler methods for assessing invasively derived left ventricular diastolic pressure (LVDP). BACKGROUND: To date, no studies have evaluated which of the various available Doppler methods are most reliable in determining LVDP in a consecutive patient population with different cardiac diseases. METHODS: LVDP was estimated by the following Doppler methods (M): (1) M1-the peak mitral regurgitant flow velocity (peak MR), (2) M2-the mitral regurgitant velocity at the time of aortic valve opening (MRAVO), (3) M3-the aortic regurgitant end-diastolic flow velocity (ARED), (4) M4-the ratio of the transmitral to mitral annular early diastolic velocity (ETM/EDTI), (5) M5-a transmitral flow velocity regression equation (RegrTM), and (6) M6-the difference of pulmonary venous and transmitral A wave duration (APV - ATM duration). For M1-M3, sphygmomanometric blood pressure was used to calculate LVDP. RESULTS: In 101 patients, the regression coefficient, standard error of estimate, and mean difference with confidence limits between Doppler and catheter-derived measurements were as follows: M1 (n = 46): r = 0.81 (P < 0.0001), 4.3 mmHg and 3.7 +/- 12.0 mmHg; M2 (n = 47): r = 0.79 (P < 0.0001), 5.4 mmHg and 1.1 +/- 11.2 mmHg; M3 (n = 20): r = 0.64 (P = 0.002), 7.8 mmHg and 4.6 +/- 17.6 mmHg; M4 (n = 50): r = 0.62 (P < 0.0001), 5.6 mmHg and 0 +/- 11.2 mmHg; M5 (n = 79): r = 0.24 (P = 0.03), 7.1 mmHg and - 0.1 +/- 16.8 mmHg; and M6 (n = 79): r = 0.22 (P = 0.05), 7.3 mmHg and 0 +/- 14.4 mmHg, respectively. CONCLUSIONS: The Doppler measurement of mitral regurgitant jets is most accurate method to estimate left ventricular filling pressure noninvasively.

Aged↗
PubMed2002

Effect of endurance training on coronary artery size and function in healthy men: an invasive followup study.

In eight healthy male volunteers (cardiologists; age 36 +/- 5 yr), bicycle spiroergometry, Doppler echocardiography, and quantitative coronary angiography with intracoronary Doppler measurements before and after completion of a physical endurance exercise program of >5 mo duration were performed. Maximum oxygen uptake increased from 46 +/- 6 to 54 +/- 5 ml x kg(-1) x min(-1) (P = 0.04), maximum ergometric workload changed from 3.8 +/- 0.3 to 4.4 +/- 0.3 W/kg (P = 0.001), and left ventricular mass index increased from 82 +/- 18 to 108 +/- 29 g/m(2) (P = 0.001). The right, left main, and left anterior descending coronary artery cross-sectional area increased significantly in response to exercise. Before versus at the end of the exercise program, flow-induced left anterior descending coronary artery cross-sectional area was 10.1 +/- 3.5 and 11.0 +/- 3.9 mm(2), respectively (P = 0.03), nitroglycerin-induced left coronary calibers increased significantly, and coronary flow velocity reserve changed from 3.8 +/- 0.8 to 4.5 +/- 0.7 (P = 0.001). Left coronary artery correlated significantly with ventricular mass and maximum oxygen uptake, and coronary flow velocity reserve was significantly associated with maximum workload.

Adenosine↗
PubMed2002

Five French versus 6 French PCI: a case control study of efficacy, safety and outcome.

We report our experience of percutaneous coronary intervention (PCI) with 5 French (Fr) guiding catheters in a retrospective analysis of consecutive cases undergoing ad hoc PCI. Results were compared with a cohort of 6 Fr PCI cases matched for age, sex and operator over the same study period. A total of 210 patients (311 lesions) underwent PCI using 5 Fr guiding catheters and 174 matched patients (300 lesions) underwent PCI with 6 Fr guiding catheters. Multivessel PCI was performed in 18% of patients in the 5 Fr group and in 26% of the 6 Fr group (p = 0.046). There was no difference in clinical, angiographic or procedural characteristics between groups. Technical success rate was superior in the 5 Fr group compared with the 6 Fr (99% versus 95%; p = 0.03). The rate of stent implantation did not differ and the 5 Fr guiding catheter did not prohibit the use of large or long stents/balloons. Failure of 5 Fr PCI in 3 cases was not due to inadequate guiding catheter support. In-hospital major adverse cardiac events (MACE) and serious femoral complications were rare and at 6-month follow-up did not differ between groups. However, compared with 6 Fr PCI, procedure time and contrast medium usage was significantly less in the 5 Fr group (contrast: 274 +/- 101 ml versus 313 +/- 124 ml; p = 0.0008; fluoroscopy time: 16 +/- 9 minutes versus 19 +/- 12 minutes; p = 0.006). We conclude that the use of 5 Fr guiding catheters is effective and safe in unselected patients undergoing PCI and may even confer certain advantages. The 5 Fr approach can be recommended for routine interventional practice.

Adult↗