Non-invasive variant of Gorlin formula can be used to identify severe aortic stenosis

Summary. In recent years the continuity equation has been established as a valuable non-invasive method for calculating aortic valve area. The continuity equation cannot be used if there is calcification or sub-valvular stenosis in the left ventricle-outflow tract, because the area of the outflow trace is not circular in those cases. The authors have tested the value of a non-invasive variant of the Gorlin formula, as an alternative method of identifying severe aortic stenosis. They examined 32 consecutive patients with aortic stenosis with both methods. Seventeen patients had severe stenosis (valve area^0–7 cm²), calculated by the continuity equation. The other 15 patients had moderate stenosis (valve area 0–7–1–0 cm²). Using the non-invasive variant of the Gorlin formula, the authors were able to identify 16 of the 17 cases with severe stenosis, thus showing that the method is useful for identifying severe aortic stenosis. (P<0–001 by x²-test).     

Epidemiology of Familial Adenomatous Polyposis in Sweden: Changes over Time and Differences in Phenotype between Males and Females

Background: The Swedish Polyposis Registry was set up in Sweden in the late 1950s to promote screening of familial adenomatous polyposis (FAP). The aim of this study was to examine the epidemiology of FAP in Sweden, including the influence of screening on morbidity and mortality in colorectal cancer (CRC). Methods: Four hundred and thirty-one patients (213 males and 218 females) with FAP from 145 families recorded by the Swedish Polyposis Registry were investigated. The effect of screening on morbidity and mortality in CRC was evaluated by comparing the 216 probands with the 215 call-up patients. Three different periods were studied: the pre-screening period (1912-1956), the first screening period (1957-1976), and the second screening period (1977-1996). Results: The mean annual incidence rates during the three periods were 0.2, 1.38, and 0.86 per million, respectively. The birth frequency was calculated to be 1 in 18,000 between 1947 and 1966, and the prevalence was 32 per million at the end of 1996. The proportion of new mutants among the FAP patients born between 1927 and 1966 was estimated to be 11%. The median age at diagnosis of probands was 39 (range, 11-71) years and did not change over time, although an increase was seen in the subgroup with CRC at diagnosis (P = 0.02). In the call-up group the median age at diagnosis was 22 (range, 3-65) years. Sixty-seven per cent of the probands and 3.3% of the call-up patients had CRC at diagnosis, and the corresponding mortality figures were 44% and 1.9%. The risk among probands of having CRC at diagnosis decreased from 81% to 49% (P = 0.0006). Female probands were diagnosed with symptoms (P = 0.03) and CRC (P = 0.04) earlier than male probands. Conclusions: A nationwide screening program facilitates detection and early diagnosis of FAP. A decrease in CRC morbidity among probands contributed to the improved prognosis. An earlier onset of symptoms and CRC in females indicate that the course of FAP is influenced by sex.     

Left radial approach for coronary angiography: Results of a prospective study

Although radial approach has been shown to be feasible for coronary angiography, angioplasty, and even stent placement, there have been no prospective evaluations of ease and safety of left radial approach for coronary angiogram. We examined procedural duration and success as well as complications in 415 consecutive patients. Radial artery occlusion was assessed immediately post-procedure and at 2 month follow-up using echo-Doppler measurements. Procedure failure rate was 9%, mean time for sheath insertion was 4.7 ± 4.7 min, and mean procedure duration was 19.1 ± 8.2 min. No major complications occurred. Asymptomatic radial artery occlusion was noted in 71% of the first 49 patients, decreased to 24% in the next 119 receiving 2,000–3,000 units of heparin, and to 4.3% in the last 210 receiving 5000 (p < 0.05). Comparison with the femoral approach in the same laboratory suggested that the radial approach took longer, but provided similarly high-quality results without great difficulty in coronary cannulation. Hence, the left radial approach for coronary angiography (with heparin administration) allows immediate ambulation and may be especially useful for outpatients and when the femoral approach is not possible. © 1996 Wiley-Liss, Inc.     

Diagnosis of renovascular hypertension by echo-Doppler velocimetry

A 13 year old boy suffering hypertension was examined for peripheral plasma renin, angiotensin-I, angiotensin-II and aldosterone. All data were within the normal range. The Captopril test and renal scintigraphy (both with and without Captopril) also showed normal patterns. Echo-Doppler velocimetry of the renal artery revealed that left renal arterial peak flow velocity was fast (3.4 m/s). The patient was therefore diagnosed with left renal arterial stenosis. Angiography demonstrated the duplex of the left renal artery and stenosis of the left lower renal artery. Percutaneous transluminal angioplasty was successfully performed.     

Errors in measurements of stroke volume for invasive and echo-Doppler evaluations of valvular regurgitant fractions. Clinical evaluation and computer simulation Intra-arterial blood pressure monitoring in the evaluation of the hypertensive athlete

The aim of this study was to compare cardiac catheterization(CATH) with 2D echo-Doppler (ED) in clinically evaluating thestroke volumes (SV) needed to calculate aortic and mitral regurgitantfractions (aortic and mitral SV for the ED method, thermodilutionand angiographic SVfor the CA TH). As there is no ‘goldstandard’ for this kind of measurement, only subjectswithout valvular regurgitation were considered. In these subjects,though the two SV measurements needed to calculate the regurgitantvolume should have been identical, there was, in fact a differencedue to the systematic and random errors of the methods. We calculatedthe mean value and the standard deviation of this differencein a series of patients without valvular regurgitation in orderto obtain an estimate of both systematic and random errors.In20 patients studied by ED a difference of 11.9±16.7 mlwas found. In 36 patients studied by cardiac catheterizationthe difference was 19.6 ± 20.1 ml. A significant systematicerror was found for both ED and the invasive method; The transmitralSV tended to be larger than the aortic and the angiographicSV larger than that obtained by thermodilution.To try to determinethe extent to which the random errors could be attributed tothe reproducibility of the measurements, we carried out computersimulations. The SVs of 50 000 hypothetical patients were randomlygenerated and then attributed a random error calculated on thebasis of the variability of the CA TH (thermodilution 4%, angiography10%) and the ED measurements (aortic annulus 6%, mitral annulus18%, mitral time velocity integral 10%, aortic time velocityintegral 8%). We obtained a simulated difference of 0.92 ±14.7 for ED and of 0.12 ±8.4 for CATH. Mean values ofsimulated differences are obviously close to zero, because ofthe absence of systematic error. The simulated and observedrandom errors for the ED method were not statistically different,while a significant difference was found between the real andthe simulated value for the CA TH. This can be explained bytaking other sources of error into consideration (differencesbetween the angiographic and thermodilution techniques, invasivetechniques interfering with haemodynamic parameters).It canbe concluded that the determination of the S Vs has too higha margin of error in both methods for it to be used in clinicalpractice for evaluating the RF. For the ED, this error is mainlydue to inaccuracy in the anatomic and flow velocity measurementswhereas, with CA TH, it is partly due to measurement reproducibilityand partly to the method itself     

Acute thrombosis of mechanical mitral valve prosthesis: echo-Doppler diagnosis and successful treatment with systemic thrombolysis.

The case of a 72-year old patient with acute heart failure due to thrombosis of the mechanical mitral prosthesis is presented. The diagnosis was made by transthoracic echocardiography. The patient refused reoperation, and systemic thrombolysis was administered. After thrombolytic infusion we observe the disappearance of the echocardiographic signs of thrombosis, with concomitant improvement of symptoms.     

Upright posture blunts postprandial splanchnic hyperemia in patients with cirrhosis and portal hypertension

The aim of this study was to compare postprandial hemodynamic changes observed during assumption of the recumbent posture and upright posture in patients with cirrhosis and portal hypertension. Eleven patients with cirrhosis and portal hypertension were studied. Echo-Doppler examinations were performed to measure flow volume in the portal vein (PV), superior mesenteric artery (SMA), and splenic artery (SA) in the fasting condition. Collateral blood flow was indirectly calculated by determining the difference between the sum of SMA, SA, and PV blood flows. After these measurements were done, each patient received a standardized liquid meal and was then randomly assigned to either maintain supine or upright posture, in a crossover design, on 2 different days (recumbent day and upright day). On each study day, the above-mentioned measurements were repeated 30 min and 60 min after the meal. PV blood flow increased significantly after the meal on the recumbent day (P < 0.01) but not on the upright day (P = 0.78). Although there were significant postprandial increases in SMA blood flow on both study days (P < 0.01, P < 0.01), the effect was less pronounced on the upright day than on the recumbent day (P < 0.01). Postprandial SA blood flow showed no change on the recumbent day (P = 0.64), but decreased significantly on the upright day (P < 0.01). The calculated postprandial collateral blood flow increased significantly on the recumbent day (P < 0.05), but showed no change on the upright day (P = 0.53). These results suggest that the upright posture blunts postprandial splanchnic hyperemia in patients with cirrhosis and portal hypertension. Received: April 13, 1998/Accepted: September 25, 1998     

Is 'diastolic heart failure' a diagnosis of exclusion? Echocardiographic parameters of diastolic dysfunction in patients with heart failure and normal systolic function

Background: Diastolic heart failure (DHF) is reported to account for 30–50% of heart failure presentations, but its prevalence in the absence of overt coronary disease is unclear. Diastolic heart failure is usually defined by exclusion (heart failure with normal left ventricular (LV) systolic function), and few studies have sought a specific diagnosis of diastolic dysfunction. The objective of the present study was to determine the prevalence of isolated DHF and characterise LV diastolic function in patients without clinical evidence of coronary disease, who were referred for LV function assessment.

Methods: Among 938 consecutive patients referred for assessment of LV function, diastolic dysfunction was sought in patients with clinical heart failure, normal systolic function, and no valvular or coronary disease. The evaluation was based on measurement of early (E) and late (A) transmitral velocities and E wave deceleration time (DT). Pulmonary vein systolic, diastolic and atrial reversal velocities were used to differentiate pseudonormal filling in patients with normal E/A and DT.

Results: Normal LV systolic function was present in 331 patients (35%), of whom 53 (6%) met criteria for a clinical diagnosis of DHF. Diastolic dysfunction was confirmed by echocardiography in 38 patients (72% of clinical DHF patients), of whom 27 had impaired LV relaxation, 10 had pseudonormal filling, and one had restrictive filling. Diastolic function was normal in 13 and indeterminate in two patients. Pseudonormal or restrictive LV filling were more prevalent in patients with acute heart failure (7/20, P < 0.05).

Conclusions: Carefully defined, isolated DHF is uncommon, but most of these patients demonstrate echocardiographic evidence of diastolic dysfunction.     

Echo-Doppler measurements of portal vein and superior mesenteric artery blood flow in humans: Inter- and intra-observer short-term reproducibility

The reproducibility of echo-Doppler measurements of portal vein and superior mesenteric artery blood flow has not been extensively studied. In the present study, two groups of subjects were examined to test inter- and intra-observer reproducibility. Each study population consisted of 15 non-portal hypertensive and 15 portal hypertensive subjects. With a standardized technique, the cross-sectional area and velocity of blood flow in the portal vein and superior mesenteric artery were recorded in triplicate by skilled operators. The flow volume of each vessel was calculated by multiplying the cross-sectional area by the velocity of blood flow. The measurements were performed in a blind fashion over a 60 min period. The reproducibility of measurements was assessed by calculation of intraclass correlation coefficients and coefficients of variation. The intra-observer intraclass correlation coefficient was 0.77 for portal vein blood flow and 0.84 for superior mesenteric artery blood flow, suggesting good reproducibility. The intra-observer coefficient of variation was 11 and 9%, respectively. In contrast, the interobserver intraclass correlation coefficient was calculated to be 0.49 for portal blood vein blood flow and 0.57 for superior mesenteric artery blood flow, indicating fair reproducibility. In addition, the interobserver coefficients of variation were calculted to be 20 and 18%, respectively. These data suggest that intra-observer reproducibility in echo-Doppler measurements of portal vein and superior mesenteric artery blood flow is acceptable but inter-observer reproducibility is not. Examination by a single operator, rather than multiple operators, is therefore advisable. Even when measurements are performed by a single investigator an approximate variance of 10% in the measurement in a single subject should be expected.     

Portal Hypertension and Esophageal Varices in Cystic Fibrosis: Unreliability of Echo-Doppler Flowmetry

To investigate the role of echo-Doppler flowmetry in evaluating patients with cystic fibrosis and portal hypertension at risk of esophageal varices, we studied 26 subjects divided in 3 groups: 9 with portal hypertension and esophageal varices, 8 with chronic liver disease without varices, and 9 without chronic liver disease. Spleen size, diameter, blood velocity, and flow rate of portal, splenic, and superior mesenteric veins were recorded. In patients without chronic liver disease Doppler measurements were repeated on 2 different days to assess intraobserver variability. Significant differences among the three groups were found for mean values of spleen size and diameters of portal, splenic, and superior mesenteric veins. Nevertheless, a considerable overlapping of individual data was observed. No differences were observed in mean hemodynamic measurements, except for blood velocity in portal vein and flow rate in splenic vein. The intraobserver variability for repeated Doppler measurements was clinically unacceptable for most of the variables studied. Echo-Doppler assessment of splanchnic flow seems to be an unreliable tool in the management of cystic fibrosis patients with portal hypertension at risk of esophageal varices.