Role of Experience, Leadership and Individual Protection in the Cath Lab--A Multicenter Questionnaire and Workshop on Radiation Safety.

PURPOSE: Radiation exposure in invasive cardiology remains considerable. We evaluated the acceptance of radiation protective devices and the role of operator experience, team leadership, and technical equipment in radiation safety efforts in the clinical routine. MATERIALS AND METHODS: Cardiologists (115 from 27 centers) answered a questionnaire and documented radiation parameters for 10 coronary angiographies (CA), before and 3.1 months after a 90-min. mini-course in radiation-reducing techniques. RESULTS: Mini-course participants achieved significant median decreases in patient dose area products (DAP: from 26.6 to 13.0 Gy × cm(2)), number of radiographic frames (-29%) and runs (-8%), radiographic DAP/frame (-2%), fluoroscopic DAP/s (-39%), and fluoroscopy time (-16%). Multilevel analysis revealed lower DAPs with decreasing body mass index (-1.4 Gy × cm(2) per kg/m(2)), age (-1.2 Gy × cm(2)/decade), female sex (-5.9 Gy × cm(2)), participation of the team leader (-9.4 Gy × cm(2)), the mini-course itself (-16.1 Gy × cm(2)), experience (-0.7 Gy × cm(2)/1000 CAs throughout the interventionalist's professional life), and use of older catheterization systems (-6.6 Gy × cm(2)). Lead protection included apron (100%), glass sheet (95%), lengthwise (94%) and crosswise (69%) undercouch sheet, collar (89%), glasses (28%), cover around the patients' thighs (19%), foot switch shield (7%), gloves (3%), and cap (1%). CONCLUSION: Radiation-protection devices are employed less than optimally in the clinical routine. Cardiologists with a great variety of interventional experience profited from our radiation safety workshop - to an even greater extent if the interventional team leader also participated. KEY POINTS: Radiation protection devices are employed less than optimally in invasive cardiology. The presented radiation-safety mini-course was highly efficient. Cardiologists at all levels of experience profited from the mini-course - considerably more so if the team leader also took part. Interventional experience was less relevant for radiation reduction. Consequently both fellows and trainers should be encouraged to practice autonomy in radiation safety.

ECG-gated coronary angiography enables submillisievert imaging in invasive cardiology.

BACKGROUND: The median dose area products (DAP) and effective doses (ED) of patients arising from coronary angiography (CA) are considerable: According the 2013 National German Registry, they amount to 19.8 Gy × cm(2) and 4.0 mSv, respectively. METHODS: We investigated the feasibility of prospective electrocardiogram (ECG)-gated coronary angiography (CA)-a novel technique in invasive cardiology-with respect to possible reduction in irradiation effects. Instead of universally fix-rated radiographic acquisition within 7.5-15 frames/s, one single frame/heartbeat was triggered toward the diastolic moment immediately before atrial contraction (77 % of ECG-RR interval) most likely to provide motion-free and hence optimized resolution of the coronary tree. For 200 patients (body mass index 27.8 kg/m(2), age 67.5 years, male 55 %, 68 bpm) undergoing ECG-gated CA, we measured various median (interquartile range) parameters for radiation exposure. RESULTS: The total DAP was 0.64 (0.46-1.00), radiographic fraction was 0.30 (0.19-0.43), and fluoroscopic fraction was 0.35 (0.21-0.57) Gy × cm(2). Radiographic imaging occurred within 21.7 s (17.1-26.3), with 25 frames (20-30) over the course of 7 runs (6-8). Fluoroscopy time was 119 s (94-141). Radiographic DAP was 12.6 mGy × cm(2)/frame and 13.8 mGy × cm(2)/s. Fluoroscopic DAP was 0.8 mGy × cm(2)/pulse and 3.1 mGy × cm(2)/s. Patient reference point air kerma was 17.0 mGy (11.1-28.1) and contrast volume was 70 ml (60-85). CONCLUSION: In conclusion, invasive ECG-gated coronary imaging is feasible in clinical routine and enables patient EDs of approx. 3 % of typical values in invasive cardiology: 0.13 mSv (0.09-0.20).

Latest-generation catheterization systems enable invasive submillisievert coronary angiography.

BACKGROUND: The radiation risk of patients undergoing invasive cardiology remains considerable and includes skin injuries and cancer. To date, submillisievert coronary angiography has not been considered feasible. PATIENTS AND METHODS: In 2011, we compared results from 100 consecutive patients undergoing elective coronary angiography using the latest-generation flat-panel angiography system (FPS) with results from examinations by the same operator using 106 historic controls with a conventional image-intensifier system (IIS) that was new in 2002. RESULTS: The median patient exposure parameters were measured as follows: dose-area product (DAP) associated with radiographic cine acquisitions (DAP(R)) and fluoroscopy (DAP(F)) scenes, radiographic frames and runs, and cumulative exposure times for radiography and fluoroscopy. On the FPS as compared to the traditional IIS, radiographic detector entrance dose levels were reduced from 164 to 80 nGy/frame and pulse rates were lowered from 12.5/s to 7.5/s during radiography and from 25/s to 4/s during fluoroscopy. The cardiologist's performance patterns remained comparable over the years: fluoroscopy time was constant and radiography time even slightly increased. Overall patient DAP decreased from 7.0 to 2.4 Gy × cm(2); DAP(R), from 4.2 to 1.7 Gy × cm(2); and DAP(F), from 2.8 to 0.6 Gy × cm(2). Time-adjusted DAP(R)/s decreased from 436 to 130 mGy × cm(2) and DAP(F)/s, from 21.6 to 4.4 mGy × cm(2). Cumulative patient skin dose with the FPS amounted to 67 mGy, and the median (interquartile range) of effective dose was 0.5 (0.3 … 0.7) mSv. CONCLUSION: Consistent application of radiation-reducing techniques with the latest-generation flat-panel systems enables submillisievert coronary angiography in invasive cardiology.

Long-term efficacy of a mini-course in radiation-reducing techniques in invasive cardiology.

PURPOSE: To validate the long-term efficacy of a 90-min. educational mini-course in less-irradiating cardiac interventional techniques. MATERIALS AND METHODS: Before, two months after, and two years after the mini-course (periods I, II, and III), we analyzed the following radiation dose parameters for ten coronary angiographies (CA), performed by each of 7 cardiologists: total dose-area product (DAP), radiographic and fluoroscopic DAP fractions, number of radiographic frames and runs, and fluoroscopy time. RESULTS: The median patient DAP for periods I, II and III was 31.4, 15.8 and 8.5 Gy × cm2, respectively. The long-term effect was related to shorter median fluoroscopy times (180, 172, and 120 s), shorter (57, 52, and 45) and fewer (12, 12, and 10) radiographic runs, consistent collimation and restriction to an adequate image quality. Both radiographic DAP/frame (28.7, 17.0, and 18.4 mGy × cm2) and fluoroscopic DAP/second (45.7, 24.2, and 10.0 mGy × cm2) decreased significantly. The multivariate linear regression analysis confirmed the increasing efficacy of the mini-course itself (-44.6 and -60.7%), and revealed a decreasing influence of the interventionalist's experience (-8.6% and -4.9% per 1,000 CAs, lifelong performed until the mini-course). The number of CAs performed after the mini-course did not influence the long-term DAP results. CONCLUSION: The presented educational mini-course allows a significant, long-lasting, and apparently ongoing reduction of patient radiation exposure due to CA. A self-surveillant documentation of relevant radiation parameters is well suited to monitor and improve each operator's individual long-term radiation-reducing efforts.

Radiation-reducing planning of cardiac catheterisation.

Any radiation exposition for medical purposes should be kept as low as is reasonably achievable. Mean patient radiation exposure of diagnostic cardiac catheterisation is high (16-106 Gy x cm2) and for this reason the International Commission on Radiological Protection (ICRP) recommends credentialing radiation protection training programmes. Twenty cardiologists each documented various dose parameters of 10 cardiac catheterisations, before and after a 90-minute mini-course of the ELICIT study group ("Encourage to Less Irradiating Cardiologic Interventional Techniques"), and could achieve a reduction of the mean dose-area product by 15.9+/-9.0 Gy x cm2, equivalent to 47%. The presented radiation-reducing planning of invasive cardiac catheterisation for this reason is the first one validated in clinical routine and consists of 6 standard runs--one for the left ventricle, 3 and 2 for the left (LCA) and right coronary artery (RCA), respectively--depending on anatomy and findings supplemented by 1...4 special projections. The caudal posteroanterior (PA) view documents the left coronary main stem, proximal and distal left anterior descending artery (LAD), and proximal and mid circumflex segments. The cranial PA view however is suitable for the left coronary orifice, circumflex periphery, LAD, all diagonal bifurcations, and collateral pathways towards the RCA. LCA standard angiography is completed by lateral 90 degrees/0 degrees left anterior oblique (LAO) angulation. The 60 degrees/0 degrees LAO angulation visualises the right posterolateral artery (RPL) and the RCA to its bifurcation. The more proximal one finds the bifurcation, the more the second standard cranial PA view for RCA should vary towards the cranial right anterior oblique (RAO) and finally 30 degrees/0 degrees RAO view. The efficiency of these less-irradiating angulations are improved by radiation-reducing techniques as follows: restriction to essential radiographic frames and runs, consistent collimation to the region of interest--particularly during coronary intubation--, adequate instead of best possible image quality, short skin-to-image-intensifier distance, inspiration during radiography, preference for projections that rotate out the spine, optimisation of fluoroscopy time, well-experienced and well-rested interventionists.

[Fluoroscopy time -- an overestimated factor for patient radiation exposure in invasive cardiology]. / Durchleuchtungszeit -- Ein überschätzter Parameter der Patientendosis in der invasiven Kardiologie.

PURPOSE: To analyze the effects of an optimized fluoroscopy time on patient radiation exposure in the course of coronary angiography (CA) and percutaneous coronary interventions (PTCA), in comparison to those with consistent collimation to the region of interest (ROI). Furthermore, to analyze efforts concerning reduction of radiographic frames as well as concerning adequate instead of best possible image quality. MATERIAL AND METHODS: For 3,115 elective CAs and 1,713 PTCA performed by one interventionist since 1997, we documented the radiographic dose-area products (DAP (R)) and fluoroscopic dose-area products (DAP (F)), the number of radiographic frames and the fluoroscopy times during selected 2-month intervals. Under conditions of constant image intensifier entrance dose, levels of DAP (R)/frame and DAP (F)/s represent valid parameters for consistent collimation. RESULTS: In 1997, the mean baseline values of DAP for elective CA and PTCA amounted to 37.1 and 31.6 Gy x cm (2), respectively. A reduction of mean fluoroscopy times from 264 to 126 seconds for CA and from 630 to 449 seconds for PCI, both resulted in an overall DAP-reduction of merely 20 %. Optimization of mean radiographic frames from 543 to 98 for CA and from 245 to 142 for PTCA enabled reductions of 53 and 13 %, respectively. By restriction to adequate instead of best-possible image quality for coronary angiography in clinical routine, we achieved an optimized radiographic DAP/frame of 30.3 to 13.3 mGy x cm (2), which enabled a 45 % reduction of overall DAP. Most efficient however was a consistent collimation to the ROI, which resulted in a remarkable radiation reduction by 46 % for CA and by 65 % for PTCA. CONCLUSIONS: Radiation-reducing educational efforts in the clinical routine of invasive cardiology should -- against widely held opinion -- focus less exclusively toward a reduction of fluoroscopy time but more efficiently toward consistent collimation to the region of interest, reduction of radiographic frames and restriction to an adequate instead of best-possible image quality.

[Personal operator dose in invasive cardiology as a function of body height and tube angulation]. / Höhe und Röhrenangulation als die Determinanten der möglichen Untersucher-Ortsdosisleistung in der invasiven Kardiologie.

PURPOSE: To map in an experimental setting of the local personal operator dose for 55 selected tube angulations as a function of body height above ground. MATERIALS AND METHODS: On an Alderson-Rando phantom representing the patient, we performed measurements of fluoroscopy scatter radiation ( micro Sv/h) at the operator's position, for the range of 20 - 200 cm body height, for all tube angulations in 30 degrees steps from right anterior oblique (RAO) 90 degrees to left anterior oblique (LAO) 90 degrees position, and for planes angulated cranially (+) and caudally (-) by 10 degrees, 20 degrees, 30 degrees, and 40 degrees, unless rendered unfeasible by geometric circumstances. RESULTS: Radiation exposure to the operator is lowest between postero-anterior (PA) 0 degrees and RAO 30 degrees angulation, and continuously increases by a factor of approx. 2 towards steep RAO, and to factors of 5 - 10 towards steep LAO views. Craniocaudal angulation at 30 degrees likewise generates personal dose levels 2 - 3 times as high. For all body heights and all LAO tube angulations, the corridor between 0 degrees - 10 degrees caudal angulation generates the least personal scatter dose, likewise irrespective of body height and craniocaudal tube angulations, the corridor between 0 degrees PA - 30 degrees RAO angulation. RAO angulations, however, being inverse to the respective 90 degrees LAO angulations, are generally 4 to 5 times less radiation extensive. Peak levels of the local personal dose vary from 160 cm body height for steep cranial LAO 90 degrees /30 degrees + views (3,500 microSv/h), to 50 cm for cranial PA 0 degrees /30 degrees + (400 micro Sv/h), and to > or = 170 cm (600 micro Sv/h) and < or = 40 cm (300 microSv/h) for steep cranial RAO 90 degrees /30 degrees + views. Caudal angulations generate slightly lower doses, with peak levels at 120 cm for LAO 90 degrees /30 degrees - views (3,000 microSv/h), at 50 cm for PA 0 degrees /30 degrees - views (300 micro Sv/h), and above 170 cm (900 micro Sv/h) and below 40 cm (500 microSv/h) for steep caudal RAO 90 degrees /30 degrees - views. CONCLUSION: The present experimental study on scatter radiation to the operator, as a function of body height and tube angulation, offers a representative data tool for all interventionists for use in invasive cardiology, to confirm the radiation safety of their favored coronary views, or to encourage less radiation-intensive angulations. Moreover, it provides new knowledge about special risks for crucial body regions and enables effective radiation protection strategies.

Predialing the number of cinegraphic frames enables an effective patient dose due to coronary angiography of 0.8 mSv.

PURPOSE: To investigate the effect of a new device for predialing the number of cinegraphic frames before each coronary angiogaphy, with the objective of reducing the patient dose area product (DAP) from coronary angiography, which typically requires 1000 to 2350 cinegraphic frames. That DAP is high and stated to be between 15.6 to 106.3 Gy x cm (2). Applying the accepted DAP-to-ED conversion factors, for the thoracic region of approximately 0.20 mSv/Gy x cm (2), this corresponds to a mean effective dose (ED) in the range of 3.1 to 21.3 mSv. MATERIAL AND METHODS: For patients undergoing elective coronary angiography, we compared various parameters of radiation exposure obtained with judicious radiation reducing standard techniques (n = 106) and with an additional new rotary switch for predialing the number of cinegraphic frames (n = 106). RESULTS: The patient radiation dose was significantly lower with the new device, with the mean DAP reduced to 5.5 from 9.1 Gy x cm (2). The corresponding reducation of the mean DAP for left ventriculography and coronary angiography was 1.3 from 1.7, and 4.2 from 7.4 Gy x cm (2), respectively. The number of cinegraphic frames was 98 vs. 184, whereas the number of cinegraphic runs and the fluoroscopy time were comparable. CONCLUSION: Predialing the cinegraphic frame number before each cinegraphic run enables a reduction of the patients effective dose from coronary angiography to 0.8 mSv, i. e. to 57 % of the baseline value and far below typically reported values.

Standardization of occupational dose to patient DAP enables reliable assessment of radiation-protection devices in invasive cardiology.

PURPOSE: With the aim of assessing the effectiveness of radiation-protection devices in invasive cardiology, the goal of this study was to validate relative parameters for operator occupational exposure, standardized to the patient's primary dose. MATERIAL AND METHODS: One of these parameters was the local dose, measured in air at the operator's position per dose area product (DAP), applied to a male anthropomorphic Alderson-Rando phantom for simulation of coronary angiography. The second parameter was personal occupational dose to the operator per DAP, measured by thermoluminescence dosimeter stripes during 121 procedures in routine clinical work. RESULTS: The local and personal doses per unit DAP - using typical 0.5-mm lead overcouch and undercouch protection - were comparable (left eye 180 vs. 360, thyroid 260 vs. 260, left shoulder 280 vs. 150, chest 400 vs. 500, hands 400 vs. 550, waist 900 vs. 400 nSv/Gy x cm (2)). The results, however, were far lower than typically reported values. Our findings therefore disclose a typically inadequate use or acceptance by individual operators of available table-attached lead protection devices, and of ceiling-attached lead-glass screens. The additional use of individual 1.0-mm lead-equivalent garments reduced local doses to levels between 1. 10 %. CONCLUSIONS: DAP-standardized dose parameters - determined experimentally (phantom measurements), or in routine clinical work - are not appreciably influenced by the equipment age and type, or by the image-intensifier entrance dose rate of the respective catheterization system. They are consequently best suited for obtaining eloquent comparisons of various radiation-protection devices, and for reliable estimation of local scatter radiation exposure by simple documentation of intervention DAP.

Radiation exposure benefit of a lead cap in invasive cardiology.

BACKGROUND: Occupational head exposure to radiation in cardiologists may cause radiation induced cataracts and an increased risk of brain cancer. OBJECTIVE: To determine the effectiveness of 0.5 mm lead equivalent caps, not previously used in invasive cardiology, in comparison with a 1.0 mm lead equivalent ceiling mounted lead glass screen. DESIGN: An anthropomorphic Alderson-Rando phantom was used to represent the patient. Scatter entrance skin air kerma to the operator position (S-ESAK-O) was measured during fluoroscopy for all standard angulations and the S-ESAK-O per dose-area product (DAP) calculated, as applied to the phantom. RESULTS: Measured mean (SD) left/right anterior oblique angulation ratios of S-ESAK-O without lead devices were 23.1 (10.1), and varied as a function of tube angulation, body height, and angle of incidence. S-ESAK-O/DAP decreased with incremental operator body height by 10 (3)% per 10 cm. A 1.0 mm lead glass shield reduced mean S-ESAK-O/DAP originating from coronary angiography from 1089 (764) to 54 (29) nSv/Gy x cm2. A 0.5 mm lead cap was effective in lowering measured levels to 1.8 (1.1) nSv/Gy x cm2. Both devices together enabled attenuation to 0.5 (0.1) nSv/Gy x cm2. The most advantageous line of vision for protection of the operator's eyes was > or = 60 degrees rightward. CONCLUSIONS: Use of 0.5 mm lead caps proved highly effective, attenuating S-ESAK-O to 2.7 (2.0) x 10(-3) of baseline, and to 1.2 (1.4) x 10(-3) of baseline where there was an additional 1.0 mm lead glass shield. These results could vary according to the x ray systems used, catheterisation protocols, and correct use of radiation protection devices.

Effective techniques for reduction of radiation dosage to patients undergoing invasive cardiac procedures.

The goal of this study was to improve radiation dose reduction techniques in invasive cardiology and after patients' radiation data had approached minimal levels, to evaluate predictors of their radiation exposure resulting from invasive cardiac procedures. Over the course of 1 year (and 1996 procedures) we minimized cinegraphic frames and runs, as well as fluoroscopy time, and trained ourselves to achieve effective fluoroscopy-saving positioning of blinds and filters toward the regions of interest. We were consequently able to reduce the mean dose-area products (DAP) for coronary angiography and angioplasty, combined interventions, high-frequency rotational atherectomy, and excimer laser angioplasty: from levels of 53.9 Gy cm(2), 79.6 Gy cm(2), 112.3 Gy cm(2), 119.4 Gy cm(2), and 168.0 Gy cm(2) as currently reported in the literature, to 12.9 Gy cm(2), 13.3 Gy cm(2), 25.9 Gy cm(2), 33.0 Gy cm(2), and 27.1 Gy cm(2), respectively. The mean DAP due to interventions in acute myocardial infarction was 38.3 Gy cm(2). DAP was influenced by body mass index, complexity of coronary artery disease, tube angulation, documented structure, coronary recanalization, emergency circumstances, and the percutaneous transluminal coronary angioplasty (PTCA) target vessel involved, but not by stent implantation. By favouring radiation-reducing cranial posteroanterior views over standard left anterior oblique views for visualization of the left anterior descending and the diagonal artery, we consequently achieved mean PTCA-DAPs of 10.4 Gy cm(2) and 8.6 Gy cm(2), respectively: levels significantly lower than those for PTCA of the right coronary artery (13.3 Gy cm(2)), left circumflex artery (13.7 Gy cm(2)), and obtuse marginal branch (16.9 Gy cm(2)). In conclusion, enhanced knowledge of radiation dose-reduction techniques significantly reduces patient radiation hazards in invasive cardiology.

Short communication: time of day influences patient radiation exposure from percutaneous cardiac interventions.

The objective of this study was to investigate the influence of time of day on patient radiation exposure due to cardiac interventions. The elective interventional workload of one experienced cardiologist documented over the course of 4 months amounted to 325 diagnostic catheterizations and 145 percutaneous coronary interventions (PCI). All radiation parameters documented during diagnostic coronary angiography remained constant throughout the entire day. In contrast, for PCI measurements made from 7:00 a.m. to 1:00 p.m., our study revealed a mean overall dose-area product (DAP) of 11.8+/-6.8 Gy cm(2) (n=115). These radiation exposure levels increased significantly later in the afternoon (n=30) by 28% to a level of 15.0+/-11.1 Gy cm(2) (p<0.045). Cinegraphic DAP increased from 3.7+/-2.7 Gy cm(2) to 5.0+/-3.2 Gy cm(2) (p<0.033). The number of cinegraphic runs and frames rose from 7.9+/-2.9 to 9.1+/-3.1 (p<0.025), and from 136+/-63 to 164+/-70 (p<0.014), respectively. The following conclusion is warranted by our data and should now be confirmed in a wider multicentre study: radiation protection of the patients could be influenced by the fatigue of the cardiologist conducting the procedure. To enhance patient radiation safety, elective percutaneous angioplasty should be scheduled for the first 6 h of the interventionalist's occupational workload. Diagnostic interventions may be safely scheduled later.

High-energy eccentric excimer laser angioplasty for debulking diffuse iIn-stent restenosis leads to better acute- and 6-month follow-up results.

BACKGROUND: Restenosis of diffuse in-stent stenosis (> 10 mm) treated with percutaneous transluminal coronary angioplasty (PTCA) is as high as 80%. The excessive tissue-hyperplasia led to debulking before PTCA. Because debulking is limited by the intensity and applicability of its use, the large debulking trials were criticized and showed no major benefit. Considering that a significantly greater diameter than its own diameter can be ablated by the Eccentric Excimer Laser (eccELCA), we evaluated its effectiveness and safety in a prospective study. METHODS: Thirty-nine patients with diffuse in-stent restenosis (3.4 +/- 0.6 mm diameter; 14 +/- 9 mm in length) were treated by EccELCA followed by PTCA. In addition to clinical/angiographic target lesion revascularization (TLR) and major adverse cardiac events (MACE), the study endpoints were diameter stenosis (DS) and minimal lumen diameter (MLD), which were calculated before EccELCA, after EccELCA, after adjunctive PTCA and at 6-month follow-up. RESULTS: Procedural success was 99.8%. Delivered laser energy was 2,134 +/- 856 Joules. DS decreased from 84 +/- 14% to 23 +/- 11% after eccELCA (p = 0.0018) to 9 +/- 5% after PTCA (p = 0.001) and was 31 +/- 12% at follow-up (p = 0.0041). MLD increased from 0.7 +/- 0.2 mm to 2.2 +/- 0.4 mm after EccELCA (p = 0.0017), to 2.7 +/- 0.4 mm after PTCA (p = 0.001) to 1.7 +/- 0.3 mm at follow-up (p = 0.0049). Maximal balloon inflation pressure was 9.4 +/- 4.0 atmospheres. At follow-up angiography, TLR = 23.1%, clinical TLR = 12.8%, and MACE = 0%. CONCLUSION: Due to a greater debulking effect, additional lumen gain can be achieved immediately and at follow-up through the high-energy use of EccELCA for debulking and through the use of lower balloon inflation pressures for adjunctive PTCA. Clinical and angiographic TLR is significantly lower than other debulking techniques or PTCA alone and comparable with local irradiation therapy.

[Radiation burden in invasive cardiac diagnosis: extent, factors of influence and references for minimizing radiation dosage]. / Strahlenbelastung invasiver kardialer Diagnostik: Grössenordnung, Einflussfaktoren und Hinweise zur Minimierung der Strahlendosis.

Despite great effort concerning quality control in diagnostic radiology, there exist only a few studies giving reliable details about x-ray exposure during heart-catheterization. The mean radiation dose-area product of 100 patients (male 65%, middle-aged 60.7 +/- 10.4 years) investigated was irrespective the technique according to Sones or Judkins 45.2 +/- 14.7 Sv x cm2. In comparison to an optimated x-ray chest the local x-ray entrance-expositions in case of changing (90 mSv) and constant (300 mSv) projections were 300- and 1000-fold respectively. Concerning the dose-area product and the effective dose the multiplicative factor reached 160 and 100 respectively. Radiation entrance-exposure during cinematography was 15-fold as during x-ray-examination sequences. The cinematographic radiation dose was influenced significantly by location of the contrasted coronary artery (p < 0.001) and plane of projection (p < 0.001): intensive in entrance surface dose were projections x-raying spinal column and sternum (RCA in PA- and LCA in LAO-projection). Independent variables were body mass index (BMI, p < 0.001) and sex (p < 0.005), but not age. X-ray-dose of heart catheterization was lower in women than in men, this fact being only significant in the elderly (> 60 years), indicating an effect of postmenopausal osteoporosis. An effective minimization of x-ray exposition in heart catheterization can be realized by avoiding needless cine-sequences (25-35%), rotating out bone structures of the x-ray beam ( < or = 22%) and reduction of overweight (BMI 35 > 23 kg/m2: 25-35%).

[The diagonal ear lobe crease for evaluating coronary risk]. / Die diagonale Ohrläppchenfalte in der Bewertung des Koronarrisikos.

UNLABELLED: Though the predictive value of a diagonal earlobe crease (ELC) concerning coronary heart disease (CHD) is assessed controversially and seems to be influenced by age and ethnic origin, the ELC is mainly regarded as a reliable and valid sign of CHD. 670 patients, the greatest collective so far undergoing coronary angiography, were investigated prospectively with respect to the correlation between ELC and a hemodynamically relevant CHD (coronary diameter stenosis > 70%). In presence of ELC, CHD was observed in 55.0%, in its absence in 55.9% (One-vessel-disease (1-VD) 25.8% vs 26.7%, 2-VD 14.5% vs 14.4%, > 2-VD 14.8% vs 14.8%; n.s.). ELC itself was dependent on age (p < 0.000009), overweight (body mass index (BMI) > 25 kg/m2, p < 0.034) and hyperuricemia (> 7.0 mg%; p < 0.05), but not influenced by sex and other coronary risk factors such as smoking, diabetes, hypercholesterinemia and hyperlipoidemia, physical in-activity and family history of CHD. Actual just as former smoking and male sex are associated positively to CHD, whereas diabetes, hypercholesterinemia and hyperlipoidemia seem to predict a two-or multivessel disease: this emphasizes the validity of our data. CONCLUSION: The ear-lobe crease is associated with age and overweight, but does not predict a hemodynamically relevant coronary heart disease.

Endothelium-mediated dilations contribute to the polarity of the arterial wall in vasomotion induced by alpha 2-adrenergic agonists.

We tested whether or not an endothelium-mediated dilation is involved in the response of intact arteries to alpha-adrenergic stimulation, by separately applying agonists to the luminal or adventitial side of the arterial wall. Cumulative dose-response curves of the alpha 1-agonists l-phenylephrine or cirazoline applied luminally in rat tail arteries and in side branches of canine femoral arteries were identical to those obtained by adventitial application in the intact arteries, and were not modified by removal of the endothelium (eliminating acetylcholine-induced dilations). Constrictions induced by the alpha 2-agonists UK-14,304 or azepexole applied luminally were significantly lower than those induced by adventitial application, and were augmented significantly by removal of the endothelium. Half-maximally precontracted arteries were dilated by addition of alpha 2-agonists to the luminal perfusate; these dilations were abolished by removal of the endothelium. It is concluded that the functional polarity of the vascular wall of these arteries in response to alpha 2-agonists results from the release of a dilatory signal from the endothelial cells, counteracting the direct contractile activation of the adjacent smooth muscle cells by the agonists.