Real-time contrast-enhanced sonography of renal transplant recipients predicts chronic allograft nephropathy.

Real-time contrast-enhanced sonography (RT-CES) can assess microvascular tissue perfusion using gas-filled microbubbles. The study was performed to evaluate the feasibility of RT-CES in detecting chronic allograft nephropathy (CAN) in comparison to color Doppler ultrasonography (CDUS). A total of 26 consecutive renal transplant recipients were prospectively studied using RT-CES and conventional CDUS. Transplant tissue perfusion imaging was performed by low-power imaging during i.v. administration of the sonocontrast Optison. Renal tissue perfusion was assessed quantitatively using flash replenishment kinetics of microbubbles to estimate renal blood flow A *beta (A = peak signal intensity, beta= slope of signal intensity rise). In contrast to conventional CDUS resistance and pulsatility indices, renal blood flow estimated by CES was highly significant related to S-creatinine (r =-0.62, p = 0.0004). Determination of renal blood flow by CES reached a higher sensitivity (91% vs. 82%, p < 0.05), specificity (82% vs. 64%, p < 0.05) and accuracy (85% vs. 73%, p < 0.05) for the diagnosis of CAN as compared to conventional CDUS resistance indices. Perfusion parameters derived from RT-CES significantly improve the early detection of CAN compared to conventional CDUS. RT-CES using low-power real-time perfusion imaging is a feasible method to evaluate microvascular perfusion in renal allograft recipients.

[Various spiral CT protocols and their significance in the diagnosis of aortic dissections: results of a prospective study]. / Verschiedene Spiral-CT-Untersuchungsprotokolle und ihre Wertigkeit bei Aortendissektionen: eine prospektive Vergleichsstudie.

PURPOSE: Development of an optimized Spiral CT protocol type for the diagnosis of aortic dissections. MATERIAL AND METHODS: 121 consecutive CT examinations applying 5 different protocol types were blindly read by two experienced radiologists and then compared with: (a) 45 biplane transesophageal echocardiographies (TEE), (b) 52 transthoracic echocardiographies (TTE), (c) 52 operative findings and, furthermore, related to the clinical course over at least six months in 79 patients. RESULTS: The sensitivity of the spiral computed tomography for detection of dissection was 97% (biplane TEE: 88%), the specificity 100% (biplane TEE: 91%). In 15% dissections with atypical origin and entries (mid-portion of the aortic arch, distal thoracic aorta, etc.) were found. The optimal CT-protocol was the one with a combination of two separate but adjacent spiral scans achieving high spatial resolution for the aortic arch and enough spatial resection for the residual aorta (1. helical scan 3 mm collimation, pitch 2. 2. helical scan 5 mm collimation and pitch 2, 130 ml contrast medium at 5 ml/s) with a classification accuracy of 100%, visualization of entries of 100%, reentries of 100% (40% direct, 60% indirect). The identification of the ostia of the aortic branches were: supraaortic 93%, visceral 100%, left renal artery 100%, right renal artery 93%, iliac 64%. The CT angiography, designed as aortic arch angiography, showed a good contrast in the aortic arch vessels (79-86%) and the visceral vessels too (91%). CONCLUSION: Thoracic CT angiography can be used as gold standard in the primary evaluation of aortic dissections.

Frequency and phenotypes of familial dilated cardiomyopathy.

OBJECTIVES: This prospective study was performed to analyze the frequency and clinical characteristics of idiopathic dilated cardiomyopathy (DCM). BACKGROUND: Despite several previous reports on families with DCM, most cases are still believed to be sporadic, and specific clinical findings of the familial form are not well defined. METHODS: In 445 consecutive patients with angiographically proven DCM, we obtained detailed family histories to construct pedigrees and examined 970 first- and second-degree family members. RESULTS: Familial DCM was confirmed in 48 (10.8%) of the 445 index patients and was suspected in 108 (24.2%). The 156 patients with suspected or confirmed familial disease were younger at the time of diagnosis (p < 0.03) and more often revealed electrocardiographic changes (p = 0.0003) than patients with nonfamilial disease. Among the families of the 48 index patients with confirmed familial disease, five phenotypes of familial DCM could be identified: 1) DCM with muscular dystrophy; 2) juvenile DCM with a rapid progressive course in male relatives without muscular dystrophy; 3) DCM with segmental hypokinesia of the left ventricle; 4) DCM with conduction defects; and 5) DCM with sensorineural hearing loss. CONCLUSIONS: Up to 35% of patients with DCM may have an inherited disorder. Distinct clinical phenotypes can be observed in some families, suggesting a common molecular cause of the disease.

[Recognition of cardiac normal variants as the cause of cerebral ischemia: significance of transesophageal echocardiography]. / Die Erkennung kardialer Normvarianten als Ursache zerebraler Ischämien: Bedeutung der transösophagealen Echokardiographie.

The significance of cardiac normal variants such as patent foramen ovale (PFO), mitral valve prolapse (MVP) and atrial septal aneurysm (ASA) as potential intracardiac sources of embolism in patients with cerebral ischemia is still discussed controversially. In the present study, we determined the prevalence of PFO, MVP and ASA in patients with suspected embolic cerebral events after exclusion of cerebrovascular disease. Therefore, 164 consecutive patients with suspected embolic cerebral events as suggested by cranial computer tomography or clinical neurological examination were divided into two groups: patients with "classical" potential cardiac source of embolism (group I, n = 81, age 52 +/- 10 years) and patients without such potential cardiac sources of embolism (group II, n = 83, age 56 +/- 12 years). The prevalence of PFO, but not that of MVP and ASA, was significantly higher in group I than in group II (group I: 33.3% vs. group II: 2.4%; chi-square 88.5, p < 0.0001). In the absence of "classical" potential cardiac sources of embolism transesophageal echocardiography reveals a PFO in approximately 30% of the cases. This finding supports the significance of PFO as a potential cardiac source of embolism.

[Evaluation of atrial septum defects in adulthood using echocardiography methods]. / Beurteilung von Vorhofseptumdefekten im Erwachsenenalter mittels echokardiographischer Verfahren.

Two-dimensional and Doppler echocardiographic methods are used to noninvasively detect atrial septal defects. The value of these methods to predict the magnitude of intracardiac left-to-right shunts has not been thoroughly investigated. In this study, we derived right ventricular (RV) and septal defect dimensions, and Qp/Qs-ratios from two-dimensional and Doppler echocardiography in 30 consecutive patients (17 females, 3 males, age 37 +/- 17 years) with invasively confirmed atrial septal defects. Noninvasively obtained parameters were compared to atrial shunt size as measured by oxymetry. RV dimensions correlated only poorly (RV length: r = 0.53, p < 0.005; RV-diameter r = 0.45 p < 0.05), but septal defect dimensions (r = 0.67, p < 0.001) and Qp/Qs-index (r = 0.65, p < 0.05) correlated fairly with shunt size. RV dilatation was highly sensitive (100%) but only moderately specific (67%) as an indicator of shunts > 30%. A defect length > or = 15 mm was moderately sensitive (81%) but highly specific (100%) and a Qp/Qs-index > or = 1.45 was highly sensitive (100%) and specific (76%) to detect shunts > 30%. None of the noninvasive parameters investigated in this study was able to differentiate moderate (> 30% but < 50%) from large ( > or = 50%) intracardiac left-to-right shunts.

Cardiac activation mapping by MRI.

To establish cardiac MRI as a tool for noninvasive evaluation of activation patterns, 10 healthy volunteers were examined by cine segmented turboFLASH imaging sequences. Sequence modifications for low signal blood-pool appearance were applied, i.e., bilateral spatial saturation for segmented turboFLASH imaging. Pixelwise calculation of first-harmonic Fourier phase values (displayed as color-encoded maps) reveal either anterior septal or left ventricular free-wall sites as areas of earliest phase spreading towards posterior paraseptal sites in segmented turboFLASH scans. Phase scatter is lower in unsaturated than spatially presaturated segmented turboFLASH studies. Phase standard deviation in areas of endocardial displacement is higher in basal than apical slice positions in these scans. Early results indicate that first-harmonic Fourier phase analysis of cardiac-segmented turboFLASH MRI cine studies may provide a tool for noninvasive studies of cardiac activation sequence.

Ventilatory and pulmonary vascular response to hypoxia and susceptibility to high altitude pulmonary oedema.

Reduced tolerance to high altitude may be associated with a low ventilatory and an increased pulmonary vascular response to hypoxia. We therefore, examined whether individuals susceptible to acute mountain sickness (AMS) or high altitude pulmonary oedema (HAPE) could be identified by noninvasive measurements of these parameters at low altitude. Ventilatory response to hypoxia (HVR) and hypercapnia (HCVR) at rest and during exercise, as well as hypoxic pulmonary vascular response (HPVR) at rest, were examined in 30 mountaineers whose susceptibility was known from previous identical exposures to high altitude. Isocapnic HVR expressed as difference in minute ventilation related to difference in arterial oxygen saturation (delta V'E/ delta Sa,O2) (L.min-1/%) was significantly lower in subjects susceptible to HAPE (mean +/- SEM 0.8 +/- 0.1; n = 10) compared to nonsusceptible controls (1.5 +/- 0.2; n = 10), but was not significantly different from subjects susceptible to AMS (1.2 +/- 0.2; n = 10). Hypercapnic ventilatory response was not significantly different between the three groups. Discrimination between groups could not be improved by measurements of HVR during exercise (50% maximum oxygen consumption (V'O2,max)), or by assessing ventilation and oxygen saturation during a 15 min steady-state exercise (35% V'O2,max) at fractional inspiratory oxygen (FI,O2) of 0.14. Pulmonary artery pressure (Ppa) estimated by Doppler measurements of tricuspid valve pressure at an FI,O2 of 0.21 and 0.12 (10 min) did not lead to a further discrimination between subjects susceptible to HAPE and AMS with the exception of three subjects susceptible to HAPE who showed an exaggerated HPVR. It is concluded that a low ventilatory response to hypoxia is associated with an increased risk for high altitude pulmonary oedema, whilst susceptibility to acute mountain sickness may be associated with a high or low ventilatory response to hypoxia. A reliable discrimination between subjects susceptible to high altitude pulmonary oedema and acute mountain sickness with a low ventilatory response to hypoxia is not possible by Doppler echocardiographic estimations of hypoxic pulmonary vascular response.

[Parapneumonic ARDS. The radiomorphologic transition of a pneumonia into an ARDS]. / Das parapneumonische ARDS. Der radiomorphologische Ubergang einer Pneumonie in ein ARDS.

Serial chest X-rays of 14 patients with parapneumonic ARDS (PARDS) were analysed retrospectively. Typical findings on chest X-ray films occurred after a latency period of 12-24 h following the clinical start of PARDS. We found some "early signs" of PARDS, such as central interstitial paravascular edema (14/14), bilateral hilar infiltrates (9/14) and the absence of pleural effusion (12/14).

Diagnosis of left ventricular hypertrophy by echocardiography.

Left ventricular hypertrophy in systemic arterial hypertension is associated with an increased risk of morbidity and mortality due to cardiovascular disease. Therefore, the diagnosis of left ventricular hypertrophy is clinically important. In current clinical practice, echocardiography is the method of choice for diagnosing left ventricular hypertrophy. This review describes current, clinically applied techniques of measuring left ventricular mass using M-mode and two-dimensional echocardiography. Using M-mode techniques, left ventricular hypertrophy is usually present when myocardial mass estimates exceed 150 g/m2 in males and 120 g/m2 in females. Using two-dimensional echocardiography, upper limits of normal have been described to be slightly lower (102 g/m2 in males and 88 g/m2 in females). In serial clinical two-dimensional echocardiographic studies, image acquisition and quantitation predominantly determine total variability in left ventricular mass estimates. Using any single technician and any single reader, left ventricular mass estimates in normal subjects may vary by 35 g (standard deviation) between serial studies. Strategies to reduce the magnitude of this variability include increasing the number of technicians and readers acquiring and analyzing a single study.

[Percutaneous transfemoral valvuloplasty in patients with calcified aortic stenosis and significantly increased surgical risk: clinical course and value of Doppler sonography in assessment of therapeutic success]. / Perkutane transfemorale Valvuloplastie bei Patienten mit kalzifizierter Aortenstenose und deutlich erhöhtem Operationsrisiko: Klinischer Verlauf und Wertigkeit der Dopplersonographie zur Beurteilung des Therapieerfolges.

Percutaneous transluminal valvuloplasty (PTV) was performed in 24 patients (aged 67-86 years, mean: 76 +/- 5.7 years) with calcific aortic stenosis and high operative risk. The gradient between maximal left ventricular and aortic pressures (peak-to-peak gradient, PPPG) could be reduced by 52% from 73 +/- 21 to 34 +/- 12 mmHg (p less than 0.001). Peak pressure gradient (PPG), as assessed by continuous wave Doppler, could be reduced from 80 +/- 28 to 58 +/- 21 mmHg (p less than 0.001). Aortic valve area (AVA) as determined by Doppler and two dimensional echocardiography increased significantly from 0.39 +/- 0.14 to 0.61 +/- 0.3 cm2 (p less than 0.05). Clinical symptoms were found to be improved in 5 of 8 patients with impaired ejection fraction and in 11 of 16 patients with normal ejection fraction during the first week after PTV. Complications due to the procedure were surgical revision of femoral artery puncture site in one patient and hemodynamic relevant pericardial effusion in another patient. Transmitral early (E) and late (L) diastolic filling integrals were measured by pulsed Doppler: the ratio E/L decreased significantly after PTV from 0.9 +/- 0.5 to 0.63 +/- 0.31 (p less than 0.03) indicating further reduction of left ventricular early diastolic filling. Ejection fraction, stroke volume and cardiac output did not significantly change immediately after PTV.(ABSTRACT TRUNCATED AT 250 WORDS)

[Noninvasive determination of left ventricular diastolic filling parameters using Doppler echocardiography: clinical application in patients with coronary heart disease]. / Nichtinvasive Bestimmung linksventrikulärer diastolischer Füllungsparameter mittels Dopplerechokardiographie: Klinische Anwendbarkeit bei Patienten mit koronarer Herzerkrankung.

The purpose of this study was to characterize noninvasively left ventricular diastolic filling in patients with coronary artery disease (CAD), by the use of pulsed Dopplerecho. 139 consecutive patients with CAD (with myocardial infarction, MI, n = 110; without MI, n = 29) were included in the study and compared to 67 normal subjects. Analyzing age-matched subgroups, patients with CAD and MI showed a significantly lower peak early diastolic filling velocity (R) as compared to normal subjects. The ratio (E/L) of early (E) to late (L) filling velocity integral as well as the ratio of peak early (R) to peak late (A) filling velocity were significantly lower in patients with MI than in normal subjects. Furthermore, A was lower in patients with MI, as compared to patients without MI. There were no significant differences between patients with single-vessel and multi-vessel disease. The ejection fraction was not significantly related to the diastolic filling parameters. In the normal population (aged 15-66 years) all diastolic filling parameters tested showed a significant correlation with age. The best correlation was found with the E/L ratio (r = -0.63, p less than 0.001). In contrast, there was no significant correlation between age and any of the diastolic filling parameters in patients with CAD. In patients with MI and left ventricular enddiastolic pressure (LVEDP) greater than or equal to 20 mm Hg, E/L was within normal limits, however, and was higher than in patients with LVEDP less than or equal to 14 mm Hg (LVEDP greater than or equal to 20 mm Hg: 2.1 +/- 1.5 SD vs. LVEDP less than or equal to 14 mm Hg: 1.09 +/- 0.38 SD, p less than 0.003).(ABSTRACT TRUNCATED AT 250 WORDS)

Diastolic filling properties in different forms of left ventricular hypertrophy, assessed by 2-D echocardiography.

In order to study the influence of various kinds of left ventricular hypertrophy on left ventricular filling pattern, 20 patients (five dilated cardiomyopathy, five hypertension, five end-stage renal disease, five hypertrophic cardiomyopathy), and five normals were studied by M-mode and pulsed 2D-Doppler echocardiography. Left ventricular dimensions, volumes and mass were derived from standard M-mode echocardiograms. Doppler velocity measurements of mitral inflow provided calculation of left ventricular diastolic filling parameters. While left ventricular diastolic function bore no relation to the impairment of left ventricular systolic function, there was a statistically significant correlation of left ventricular mass/volume ratio and impairment of left ventricular diastolic function. In patients with hypertrophic cardiomyopathy, the parameters varied widely, and additional factors seem to determine left ventricular diastolic function in this group.

Angiotensin II control of the renal microcirculation: effect of blockade by saralasin.

The hydronephrotic rat kidney with intact circulation and innervation was split and spread out as a thin sheet in a tissue bath. The microvasculature was observed in vivo via television microscopy. We quantitated the effects of increasing concentrations (10(-9) to 10(-5) M) of saralasin (angiotensin II antagonist) applied locally in the tissue bath on microvascular diameters and on relative glomerular blood flow (measured using fluorescent labeled RBCs). Saralasin produced an increase in preglomerular diameters which was largest (37 +/- 11%) in the interlobular artery (there was no dilation in the afferent arteriole near the glomerulus), an increase in postglomerular diameters which was largest (17 +/- 4%) in the efferent arteriole near the glomerulus, and an increase in blood flow (19 +/- 4%). If these types of findings would hold for the normal kidney, it would suggest a role for angiotensin II in the control of total renal blood flow, in the regional distribution of flow, and in the control of filtration fraction. We also made control micropressure measurements using the servo-nulling approach. Pressures measured were: afferent arteriole, 65 +/- 5 mm Hg; intraglomerulus, 50 +/- 5 mm Hg; and efferent arteriole, 19 +/- 3 mm Hg. These data indicate that there is major vascular resistance near the glomerulus, especially in the efferent arteriole.

Influence of systemically applied angiotensin II on the microcirculation of glomerular capillaries in the rat.

The effect of intravenous infusion of angiotensin II on microvascular parameters of the renal microcirculation of rats was studied. With the aid of fluorescence microscopy and a high sensitivity video system we observed the passage of fluorescence-labeled erythrocytes through single glomerular capillaries on the surface of the rat kidney. From videotaped recordings, we measured the velocity and the flux of erythrocytes using a modified dual-slit technique with support of a microprocessor system. Angiotensin II was administered intravenously at a rate of either 0.2 or 0.4 microgram/min/kg of body wt. Angiotensin II decreased renal blood flow in a dose-dependent fashion (a 32% decrease with 0.2 microgram/min/kg and a 42% decrease with 0.4 microgram/min/kg). The higher rate of angiotensin II infusion had a variable effect on red cell velocity in glomerular capillaries with an overall effect to decrease velocity by 18%. Red cell flux in capillaries was similarly decreased by 25% with angiotensin II infusion. Three successive infusions of angiotensin II did not significantly diminish the effect of the peptide on red cell velocity or flux. Volume flow through the glomerular capillaries (calculated from erythrocyte velocity and vessel diameter) decreased during angiotensin II infusion (0.4 microgram/min/kg) from 3.2 to 2.4 nl/min despite no change in capillary diameter or hematocrit (ratio of erythrocyte flux to volume flow). These data indicate that alterations of the ultrafiltration coefficient (Kf) are not induced by uniform capillary vasoconstriction mechanisms, as others have suggested.