The impact of various protective tools on the dose reduction in the eye lens in an interventional cardiology-clinical study.

The aim of the study was to check, in clinical practice, the potential for the dose reduction of lead eyewear and a ceiling-suspended shield used to protect the eye lens of physicians working in interventional cardiology. To this end, for the lead eyewear, the dose reduction factors were derived to correct the readings from a dosimeter used routinely outside the glasses. Four types of lead eyewear with attached loose thermoluminescent dosimeters and EYE-D dosimeters were worn by physicians in two clinical centres, for two-month periods, during coronary angiography (CA), percutaneous coronary intervention (PCI), and pacemaker procedures. In order to analyse, separately, how a ceiling-suspended lead screen absorbs the scattered radiation, a series of measurements was carried out during single CA/PCI procedures performed with and without the protection. The lead eyewear may reduce the doses to the eye closest to the x-ray tube by a factor between 1.1 and 3.4, depending on its model and the physician's position. The effectiveness of the eyewear may, however, vary-even for the same model and physician-almost twofold between different working periods. The ceiling-suspended shield decreases the doses in clinical practice by a factor of 2.3. The annual eye lens doses without the eyewear estimated from routine measurements are high-above or close to the new eye lens dose limit established by the recent EU Basic Safety Standards, even though the ceiling-suspended shield was used. Therefore, to comply with the new dose limit that is set in the Directive, protection of the eyes of physicians with high workloads might require the use of both the eyewear and the ceiling-suspended shield.

Correlation of patient maximum skin doses in cardiac procedures with various dose indicators.

In most countries of European Union, legislation requires the determination of the total skin dose received by patients during interventional procedures in order to prevent deterministic damages. Various dose indicators like dose-area product (DAP), cumulative dose (CD) and entrance dose at the patient plane (EFD) are used for patient dosimetry purposes in clinical practice. This study aimed at relating those dose indicators with doses ascribed to the most irradiated areas of the patient skin usually expressed in terms of local maximal skin dose (MSD). The study was performed in two different facilities for two most common cardiac procedures coronary angiography (CA) and percutaneous coronary interventions (PCI). For CA procedures, the registered values of fluoroscopy time, total DAP and MSD were in the range (0.7-27.3) min, (16-317) Gy cm(2) and (43-1507) mGy, respectively, and for interventions, accordingly (2.1-43.6) min, (17-425) Gy cm(2), (71-1555) mGy. Moreover, for CA procedures, CD and EFD were in the ranges (295-4689) mGy and (121-1768) mGy and for PCI (267-6524) mGy and (68-2279) mGy, respectively. No general and satisfactory correlation was found for safe estimation of MSD. However, results show that the best dose indicator which might serve for rough, preliminary estimation is DAP value. In the study, the appropriate trigger levels were proposed for both facilities.

Arterial dysfunction in syndrome X: results of arterial reactivity and pulse wave propagation tests.

OBJECTIVE: To assess arterial distensibility using pulse wave velocity (PWV) measurements and its relation with endothelium dependent vasodilatation (EDV) in patients with cardiological syndrome X. METHODS: The study group consisted of 92 patients: 52 with syndrome X (34 women, 18 men, mean (SD) age 45 (3) years) and 40 healthy volunteer controls (27 women, 13 men, mean (SD) age 41 (2) years) without risk factors of atherosclerosis and with negative ECG exercise test and normal proximal coronaries on transoesophageal echocardiography. Patients with arterial hypertension, diabetes mellitus, valvar disease, or cardiomyopathy were excluded. PWV measured by a Complior Colson device was calculated for each patient. EDV was assessed from two dimensional Doppler measurement using an Acuson Sequoia with 8 MHz linear transducer at rest, during postischaemic reactive hyperaemia, and after an oral dose of 400 micro g of glyceryl trinitrate. RESULTS: PWV was significantly higher in patients with syndrome X than in healthy subjects (9.3 (0.7) m/s v 8.2 (0.9) m/s, respectively, p < 0.001). Baseline brachial artery diameter was similar in the syndrome X and control groups (4.0 (0.6) mm v 4.08 (0.64) mm, NS). EDV was impaired in patients with syndrome X compared with controls (6.6 (3.0)% v 11.1 (3.9)%, p < 0.001). Endothelium independent vasodilatation was similar in both groups. In patients with syndrome X there was a positive correlation between PWV and the degree of EDV (r = 0.864, p < 0.001). The cut off value for PWV was 8.5 m/s, with a sensitivity of 62% and a specificity of 91%. CONCLUSIONS: EDV but not glyceryl trinitrate induced vasodilatation is decreased in patients with syndrome X. There is a strong correlation between PWV and the degree of endothelial dysfunction of peripheral arteries in patients with syndrome X. PWV assessment may be useful to identify abnormal vascular physiology in these patients.

Definition of flow parameters in proximal nonstenotic coronary arteries using transesophageal Doppler echocardiography.

Transesophageal echocardiography (TEE) enables the visualization of proximal coronary arteries. We investigated the feasibility of coronary flow evaluation using TEE, as well as to define flow parameters found in normal proximal coronary arteries. The subgroups of patients with normal proximal segments of coronary arteries were selected from the cohort of 210 patients undergoing routine coronary angiography. The left main coronary artery (LMCA), proximal segment of left anterior descending coronary artery (LAD), left circumflex artery (LCx), and right coronary artery (RCA) were analyzed separately in 147, 64, 53, and 70 patients, respectively. Proximal coronary arteries were evaluated in the transverse plane using a 5-MHz TEE probe, and the flow in normal arteries was registered using pulsed-wave Doppler. The registration of flow with pulsed-wave Doppler was feasible in 88% of studies for the LMCA, 85% for the LAD, 58% for the LCx, and 65% for the RCA. Normal flow was laminar with distinct phasic character (diastolic predominance). Mean +/- SD values of peak coronary flow velocity were (systole/diastole) for the LMCA, 36 +/- 11/71 +/- 19 cm/sec; the LAD, 31 +/- 9/67 +/- 19 cm/sec; the LCx, 36 +/- 13/75 +/- 24 cm/sec; and the RCA, 25 +/- 8/39 +/- 12 cm/sec. Peak diastolic coronary flow velocity was most significantly correlated with heart rate. Doppler evaluation of proximal coronary flow is feasible using TEE in the majority of patients. The knowledge of normal flow values, which is different for the left and the right coronary artery, provides the background for proper interpretation of flow in diseased coronary arteries.

[Can the exercise test with nitroglycerin be useful for differentiation of patients with and without changes in coronary arteries--syndrome X?]. / Czy próba wysilkowa z uzyciem nitrogliceryny moze byc przydatna w róznicowaniu chorych ze zmianami i bez zmian w naczyniach wiencowych--zespól X?

UNLABELLED: The aim of this study was to compare the results of ECG exercise test performed before and after oral administration of nitroglycerine (NTG) in patients with coronary artery disease (CAD), and patients with typical chest pain without any changes in coronary arteriography--syndrome X. We examined 98 patients with typical chest pain, positive result of ECG exercise test, then accordingly to results of coronary arteries assessed with coronary arteriography, patients (pts.) were divided into two groups: group 1--35 pts. without any changes in coronary arteriography--syndrome X, and group 2--48 pts. with significant stenosis present in one or more coronary vessels. Each patient underwent two ECG exercise tests: first without any medication and second performed average 30 minutes after first test, and 5 min after oral administration of 1 table of nitroglycerine. During both tests the following parameters were evaluated: test duration, presence of chest pain, max. ST-T changes, heart rate (HR), and systolic blood pressure (SBP). RESULTS: In group 1 after NTG time of test duration had shortened from 5.9 +/- 0.4 min to 5.7 +/- 0.6 min. We also observed an increase in max. ST-T complex depression (2.2 +/- 0.5 mm vs 2.4 +/- 0.4 mm) but these differences were not statistically significant. In CAD group, duration of test after NTG was longer (6.2 +/- 1 vs 7.4 +/- 1.2), and normalization of max. ST-T complex depressions (2.7 +/- 0.5 vs 2.0 +/- 0.3 mm) was observed p < 0.01. CONCLUSION: Our study suggests that ECG exercise test with NTG may be useful in differentiation of patients with syndrome X and patients with typical coronary artery disease.

Coronary anomalies diagnosed with transesophageal echocardiography: complementary clinical value in adults.

INTRODUCTION: Coronary arteriography remains a gold standard for the evaluation of coronary anatomy. In the case of anatomical anomalies, understanding of vessel course based upon a coronary angiogram may be difficult. Transesophageal echocardiography is a noninvasive method allowing tomographic visualization of proximal coronary arteries. Experience concerning its usefulness for the assessment of anomalous coronary arteries is limited. MATERIAL: Eleven patients with confirmed coronary anomalies studied between 1993-96 were identified in the cohort of those undergoing transesophageal echocardiography. RESULTS: Transesophageal echocardiography revealed potentially serious anomalies (origin of left or right coronary artery from contralateral aortic sinus) in 3 patients and benign in 8. Coronary ostia and proximal course could be delineated in all patients. Anatomical information was consistent between methods, except for a separate origin of the left anterior descending and circumflex artery, where the angiogram missed a very short common left main coronary artery in 2 patients. The relationship between the coronary arteries, aorta and pulmonary trunk was better defined by the echocardiogram. Doppler flow analysis allowed us to exclude anomaly-related flow disturbances. CONCLUSIONS: Transesophageal echocardiography can be considered as a noninvasive technique with the potential for anatomical and functional evaluation of anomalous proximal coronary arteries and deserves a routine use whenever such a condition is suspected. This approach may simplify invasive procedures in this patient group.

Ischaemic episodes detected by early exercise test and Holter monitoring after myocardial infarction: which are of most prognostic value?

BACKGROUND: The aim of this study was to assess the significance of ST-segment depressions (ST-SD) detected during exercise test or Holter monitoring and to determine which parameters of ST-SD are the most important prognostic factors in patients after myocardial infarction. METHODS: The study group consisted of 164 patients (126 men and 38 women) who survived their first uncomplicated myocardial infarction. Twenty-four-hour Holter monitoring on day 10 (+/- 2) after infarction and a treadmill exercise test 1 or 2 days later were performed. The following parameters of ST-SD were taken into consideration: amplitude, localization according to the area of infarction and presence or absence of concomitant angina. Patients were observed for 24 months to assess the occurrence of new cardiac events. RESULTS: In 78 patients (group I) ST-SD were detected in both Holter monitoring and the exercise test, and in 32 patients (group II) in the exercise test only. Fifty-four patients (group III) were without ST-SD. During follow-up there were 83 cardiac events in group I, 24 in group II and 16 in group III (P < 0.01, group I versus II; P < 0.0001, group I versus III; P < 0.05, group II versus III). In multivariate analysis the presence of ST-SD during Holter monitoring or the exercise test, or both, appeared to be of most prognostic significance (P < 0.0001). The number of new cardiac events was significantly higher in patients with painful ST-SD greater than 3 mm, detected outside the area of infarction (distant ischaemia). CONCLUSIONS: This study shows a significant prognostic value of early post-infarction ischaemia detected by Holter monitoring and an exercise test. Distant, painful ST-SD greater than 3 mm were more powerful determinants of poor prognosis than others. Electrode placement during Holter monitoring appears to be very important, particularly in post-infarction patients.