[Electrical myostimulation: improvement of quality of life, oxygen uptake and left ventricular function in chronic heart failure]. / Elektromyostimulation: Verbesserung von Lebensqualität, Sauerstoffaufnahme und linksventrikulärer Funktion bei chronischer Herzinsuffizienz.

AIM OF THE STUDY: Regular physical activity has found to be a strategy to increase exercise capacity in patients with chronic heart failure (CHF). Next to endurance training also electromyostimulation (EMS) of thigh and gluteal muscles results in an increased capacity in CHF patients. EMS therapy was either done by stimulating 8 major muscle groups involving also trunk and arm muscles (extended electromyostimulation (exEMS)) in comparison to EMS therapy limited to gluteal and leg muscles (limEMS). METHODS: 31 individuals completed the EMS training program. Stable CHF patients (NYHA class II-III) received either exEMS (18 patients, 11 males, mean age 59.8±13.8 years) or limEMS (13 patients, 10 males, 63.6±9.4 years). Training was performed for 10 weeks twice weekly for 20 min, the level of daily activity remained unchanged. Effects on exercise capacity, left ventricular function (EF - ejection fraction) and QoL (quality of life) were evaluated. RESULTS: QoL was found to be improved in all domains of the SF-36 questionnaire. In the exEMS group there was a significant improvement in the domain physical functioning (54.09±29.9 to 75.45±15.6, p=0.48) and emotional role (63.63±45.8 to 93.93±20.1 p=0.048). LimEMS group showed significant improvement in the domain vitality (37.5±6.9 to 52.8±12.5, p=0.02).There was a significant increase of oxygen uptake at aerobic threshold in all groups (exEMS: +29.6%, p<0.001; limEMS +17.5%, p<0.001). EF -increased from 36.94±8.6 to 42.36±9.1% (+14.7%, p=0.003) in the exEMS group (limEMS 37.7±3.6 to 40.3±5.9% [+6.9%, p=0.18]). CONCLUSION: EMS contributes to an improved quality of life and can improve oxygen uptake and EF in CHF. It may be an alternative therapy in CHF patients who are otherwise unable to undertake conventional forms of exercise training.

Left ventricular mass and oxygen uptake in top handball athletes.

The key challenge in athlete's screening is the distinction between abnormal and normal which is hindered by the fact that the adaptation to sports activity in endurance athletes is different to that in power athletes. Especially cardiomyopathies provoke changes in ECG and echocardiography (echo) at an early stage when clinical symptoms are absent. ECG and echo data and their relationship to fitness peculiar to top handball players have never been described. We studied 291 male first league handball players (32 Olympians/47 national players) (25.3±4.4 years). Check up consisted of ECG, spiroergometry and echocardiography. None had T-wave inversions, 3.1% showed early repolarisation abnormalities in the precordial leads. Sokolow-Lyon voltage criterion for left ventricular hypertrophy was positive in 19.3%. Spiroergometry showed a maximum oxygen uptake (peakVO2) of 50.3±7.7 ml/min/kg body weight. LVmass was increased in comparison to normal values. There was a correlation between peakVO2 and LVindex (p<0.001, r=0.341), (LVmass/peak VO2 p=0.053, r=0.125). A relationship between cardiac dimensions and peakVO2 could not be confirmed. In professional handball players early repolarisation abnormalities were less frequent and LVmass was increased when compared with soccer players. The need for normal values for different types of sports is crucial to guarantee a proper evaluation of athletes.

Stent restenosis and thrombosis: etiology, treatment, and outcomes.

The implementation of bare metal stents and later drug eluting stents (DES) proved to be an important step forward in reducing rates of restenosis after percutaneous coronary intervention. Despite all the benefits of DES, concerns have been raised over their long term safety as especially stent thrombosis sets patients at risk. In view of the overall low frequency of stent thrombosis, large sample sizes are needed to evaluate accurately treatment differences between stents. However, a consistent finding from randomized, controlled trials of DES versus bare metal stents is the significantly reduced reintervention rate associated with DES use. The clinical presentation of restenosis is recurrent angina or acute coronary syndrome. Optimal implantation of the stent in the vessel and adequate antiplatelet therapy are of utmost significance to provide best results. Intravascular imaging often helps to provide optimal delivery of the stent. Newer stents have now been developed. Especially DES with biogradable polymers, novel coatings of the stent, and polymer free DES have to be mentioned and early results seem to be promising. The perspective of bioresorbable DES platforms includes the additional benefits of improved recovery in vessel function and the potential for reducing the requirement for prolonged dual antiplatelet therapy. This article reviews the etiology, treatment options and outcome of in stent restenosis and gives an overview about the new developments in the field of stent technology.

[Renal sympathetic denervation--physical-antomical basics, procedure, and analysis of clinical and technical parameters on procedure success and efficacy]. / Renale sympathische Denervierung: physikalisch-anatomische Grundlagen, technisches Vorgehen und Analyse klinischer und technischer Einflussgrößen auf die Effizienz der Hochfrequenzablation.

BACKGROUND: Evidence from human and animal models indicate that excessive central sympathetic nerve activity (SNA) plays a pathogenic role in triggering and sustaining hypertension. Thus, treatments targeting this neurogenic (sympathetic) triggered hypertension were evaluated and renal sympathetic denervation (RND) showed promising results. However, little is known about the parameters influencing efficacy of high frequency energy in the arterial model. PATIENTS AND METHODS: Data from all 40 consecutive patients suffering from therapy-resistant hypertension who underwent RND and completed a 1-year follow-up were retrospectively analyzed. We focussed on procedural success, complications and efficacy (office-blood pressure, 24-h-blood pressure) and its correlations to quantity of ablations and intima media thickness. RESULTS: In all patients (65.9 ± 11.6 years (range 42-83); 72.5% male) the procedure was successful. Ablations with arterial access from the upper extremity were technically unsuccessful. With the use of 13.6 ± 1.7 (10-17) ablations, office-blood pressure (1-year) could be reduced from 162/89 mmHg to 142/82 mmHg and 24-h-blood pressure from 149/83 mmHg to 139/79 mmHg, respectively, including a medium to strong correlation to quantity of ablations (r = 0.57, r = 0.63) while documenting only a weak correlation to IMT (r = -0.29, r = -0.25). CONCLUSION: In comparison to the Simplicity studies, the hypertension lowering effects were less profound but consistently present over time in the 24-h-blood pressure assessments. The positive correlation of the quantity of ablations we found seems to be plausible regarding the unpredictable allocations of the sympathetic nerves i.e. in profoundly kinking vessels in hypertensives. The physics of high-frequency energy application in the arterial model needs further research.

The concept of an anatomy related individual arterial access: lowering technical and clinical complications with transradial access in bovine- and type-III aortic arch carotid artery stenting.

BACKGROUND: Carotid artery stenting (CAS) from the femoral approach can be anatomically very difficult and the incidence of complications is higher in patients with anatomical variations of the aortic arch, difficulties related to peripheral vascular disease and/or with access site complications. Because the typical morphology in patients with a bovine- or type-III aortic arch applies for an arterial access from the right upper extremity (e.g. radial, brachial) we evaluated success rates and safety of the right transradial access in a prospective study. PATIENTS AND METHODS: Between June 2009 and October 2010, seventeen patients (mean age 74,4 ± 9 years, 10 male) with a bovine- (n = 4) or type-III aortic arch (n = 12) underwent CAS with a planned transradial- (n = 3) or after problematic transfemoral access (n = 14). In patients with a type-III aortic arch (n = 13), the right target common carotid artery (CCA) was cannulated from the right radial artery with a 5F IMA diagnostic catheter-, in patients with a bovine aortic arch (n = 4), the left CCA was accessed from the right radial artery with a 5F Amplatz- or Judkins left catheter. In all patients a 6F- (n = 14) or 5F- (n = 3) shuttle sheath was inserted via the diagnostic catheter and a 0.035” extra-stiff guidewire. All interventions were carried out with the use of a peripheral embolization protection device (EPD). Primary study endpoints were procedural success and major adverse cardiac and cerebrovascular events (MACCE), secondary endpoints were access site complications and the mean intervention time. RESULTS: Procedural success could be achieved in all patients (100 %), MACCE and access site complications did not occur in any patient. Mean interventional time was 48 ± 18 min. CONCLUSIONS: CAS using the right transradial approach for left CAS in bovine-type aortic arch or the right transradial approach in type-III aortic arch for right CAS appears to be safe and technically feasible.

Transradial access in percutaneous coronary interventions: technique and procedure.

After showing significantly lower complication rates in diagnostic coronary angiography, the radial artery access was successfully introduced as a useful vascular access site for transradial percutaneous coronary intervention in order to enhance patients' comfort and reduce hospital workload and costs. Moreover, due to the reduced need for antiplatelet therapy cessation as a result of lower bleeding complications, patients treated with transradial access showed a significantly better cardiac outcome in randomized interventional acute coronary syndrome studies.Procedural success and postprocedural radial arteritis or radial occlusions are closely related to anatomical circumstances (e.g., anomalous radial branching patterns, tortuosity, e.g., radial loops and small radial artery diameters), or risk factors for radial spasms (e.g. smoking, anxiety, vessel diameter, age, gender) which can effectively be reduced by the use of smaller catheters (4-5 Fr) and the administration of an adjuvant pharmacological therapy before (3000 U heparin, verapamil, nitroglycerine) and after (ibuprofen) the intervention.For successful radial sheath access and transradial catheterization, it is important to use dedicated radial access needles ≤ 21-gauge and steel wires ≤ 0.018 in. In order to pass the brachiocephalic trunk without difficulties or complications and access the ascending aorta, the use of inspiration maneuvers is of central importance.

Isoprenoid depletion by statins antagonizes cytokine-induced down-regulation of endothelial nitric oxide expression and increases NO synthase activity in human umbilical vein endothelial cells.

Endothelial dysfunction and atherosclerosis are associated with an inflammation-induced decrease in endothelial nitric oxide synthase (eNOS) expression. Based on the differences between hydrophobic and hydrophilic statins in their reduction of cardiac events, we analyzed the effects of rosuvastatin and cerivastatin on eNOS and inducible NO synthase (iNOS) expression and NOS activity in TNF-alpha-stimulated human umbilical vein endothelial cells (HUVEC). Both statins reversed down-regulation of eNOS mRNA and protein expression by inhibiting HMG-CoA reductase and isoprenoid synthesis. Cerivastatin tended to a more pronounced effect on eNOS expression compared to rosuvastatin. NOS activity - measured by conversion of [(3)H]-L-arginine to [(3)H]-L-citrulline - was enhanced under treatment with both drugs due to inhibition of HMG-CoA reductase. Statin-treatment reduced iNOS mRNA expression under normal conditions, but had no relevant effects on iNOS mRNA expression in cytokine-treated cells. Rosuvastatin and cerivastatin reverse the detrimental effects of TNF-alpha-induced down-regulation in eNOS protein expression and increase NO synthase activity by inhibiting HMG-CoA reductase and subsequent blocking of isoprenoid synthesis. These results provide evidence that statins have beneficial effects by increasing eNOS expression and activity during the atherosclerotic process.

Directional atherectomy facilitates the interventional procedure and leads to a low rate of recurrent stenosis in left anterior descending and left circumflex artery ostium stenoses: subgroup analysis of the FLEXI-CUT study.

OBJECTIVES: To examine by retrospective analysis of data from the FLEXI-CUT monocentre registry whether atherectomy can effectively simplify complex stent implantation in ostial bifurcation lesions by reducing the procedure to stenting of the left anterior descending (LAD) or left circumflex (LCX) artery ostium alone. PATIENTS AND METHODS: All patients who had been enrolled in the prospective FLEXI-CUT study (directional atherectomy with adjunctive balloon angioplasty) were retrospectively analysed on the basis of significant LAD or LCX ostial stenosis (>or= 70% stenosis) deriving from an undiseased left main stem. The primary combined end point was the rate of target lesion revascularisation (TLR) and binary restenosis; secondary end points were procedural success and major adverse cardiac events (MACE) at the six-month follow up. RESULTS: Of 30 patients enrolled with significant LAD or LCX ostium stenosis, 29 were effectively treated with directional atherectomy (96.7% procedural success). All patients underwent single-vessel stenting procedures of solely the LAD or LCX ostium. At follow up, binary stenosis was 25% (6 of 24), TLR (angiographic plus clinical) 10.3% (3 of 29) and total MACE 6.9% (2 of 29). CONCLUSIONS: Directional atherectomy with single-vessel stenting procedures facilitates the interventional treatment of LAD and LCX ostium stenosis, and leads to remarkably low TLR and binary stenosis at follow up.

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.

Relation between psychological strain and carotid atherosclerosis in a general population.

OBJECTIVE: To investigate the hypothesis that psychological strain is related to carotid atherosclerosis in a large general population sample. METHODS: Intima-media thickness and the prevalence of atherosclerotic plaques in the carotid arteries were quantitatively assessed by high resolution ultrasound among 2164 participants (1112 women and 1052 men, aged 45 to 75 years) of the SHIP (study of health in Pomerania), an epidemiological survey of a random sample of the population of north eastern Germany. Psychological strain was measured by 13 items reflecting typical psychological complaints. Each item was graded by the study participants on a four point scale (from 0, absent, to 3, severe) and a psychological strain score was generated by summing these 13 items. RESULTS: Mean psychological strain score was 10.8 (7.0) (median score 10) among women and 8.5 (6.2) (median score 8) among men. Psychological strain did not predict carotid intima-media thickness among either men or women. However, after adjustment for covariates, high psychological strain and carotid plaques were independently and linearly related, with plaque prevalence odds of 1.03 (95% confidence interval (CI) 1.01 to 1.05, p = 0.009) per increment of the psychological strain score among women and 1.04 (95% CI 1.01 to 1.07, p = 0.003) among men. CONCLUSIONS: This study identified a relation between general psychological strain and carotid atherosclerosis.

[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.