Time-efficient patient-specific quantification of regional carotid artery fluid dynamics and spatial correlation with plaque burden.

PURPOSE: Low wall shear stress (WSS) and high oscillatory shear index (OSI) influence plaque formation, yet little is known about their role in progression/regression of established plaques because of lack of practical means to calculate them in individual patients. Our aim was to use computational fluid dynamics (CFD) models of patients with carotid plaque undergoing statin treatment to calculate WSS and OSI in a time-efficient manner, and determine their relationship to plaque thickness (PT), plaque composition (PC), and regression. METHODS: Eight patients (68 +/- 9 yr, one female) underwent multicontrast 3 T MRI at baseline and six-month post statin treatment. PT and PC were measured in carotid segments (common-CC, bifurcation-B, internal-IC) and circumferentially in nonoverlapping 600 angles and correlated with CFD models created from MRI, ultrasound, and blood pressure. RESULTS: PT was highest in B (2.42 +/- 0.98 versus CC: 1.60 +/- 0.47, IC: 1.62 +/- 0.52 mm, p < 0.01). Circumferentially, plaque was greatest opposite the flow divider (p < 0.01), where the lowest WSS and highest OSI were observed. In B and IC, PT was inversely related to WSS (R = -0.28 and -0.37, p < 0.01) and directly related to OSI (R = 0.22 and 0.52, p < 0.05). The total plaque volume changed from 1140 +/- 437 to 974 +/- 587 mm3 at six months (p = 0.1). Baseline WSS, but not OSI, correlated with changes in PT, necrotic tissue, and hemorrhage in B and IC, but not CC. CFD modeling took 49 +/- 18 h per patient. CONCLUSIONS: PT and PC correspond to adverse WSS and OSI in B and IC, and WSS is modestly but significantly related to changes in PT after short-term statin treatment. Regional hemodynamics from CFD can feasibly augment routine clinical imaging for comprehensive plaque evaluation.

Outcome among patients with acute renal failure needing continuous renal replacement therapy: A single center study.

Outcome of acute renal failure (ARF) and use of continuous renal replacement therapy (CRRT) have shown a consistently high mortality. (1) Evaluate the short-term patient survival. (2) Evaluate dialysis-free survival. (3) Evaluate risk factors associated with overall survival and the continued need for intermittent dialysis. We identified adults (>/=18 years) needing CRRT, treated in the critical care units of Froedtert Medical and Lutheran Hospital from January 1, 2003 till December 31, 2005. Patients were divided into two major groups needing CRRT, end stage renal disease (ESRD) (chronic dialysis) and non-ESRD with ARF. Continuous renal replacement therapy was performed with an average of 2 L replacement fluid exchanges/h. Sigma stat software was used for analysis. Comparison was done for noncontinuous variables by chi-square and t test for categorical and continuous variables, respectively. A total of 110 (ESRD 24/non-ESRD 86) patients received CRRT during study period. Over all in-hospital mortality among non-ESRD patients was 63% vs. 46% for ESRD. Among non-ESRD patients who survived, 47% needed intermittent hemodialysis on intensive care unit discharge and 28% continued to need hemodialysis at last follow-up. Among non-ESRD patients alive at discharge, those who were dialysis dependent on last follow-up were older (64.5) than those who did not require dialysis on last follow-up (58.4) P=0.347. Non-ESRD patients who died were in the hospital for an average of 17.5 days compared with 29 days for those who were discharged from the hospital. Patients with ARF needing CRRT have high in-hospital mortality. A significant percentage of patients remained dialysis dependant on last follow-up.

Pericarditis: a rare complication of methotrexate therapy.

Serositis is a rare complication of methotrexate (MTX) administration. We report a 60-year-old man with rheumatoid arthritis who developed pericarditis after taking his weekly MTX dose, which recurred within hours after 2 subsequent weekly MTX doses. Pericarditis has not recurred after discontinuance of MTX over 3 years ago. We conclude that he had MTX-induced pericarditis, based on the close temporal relationship between MTX ingestion and manifestations of pericarditis on three distinct occasions because of the previous reports of MTX-induced pericarditis and because pericarditis has not recurred after MTX withdrawal.

Amniotic Fluid Embolism.

We report a case of 34-year patient who had uncomplicated elective caesarean-section. Postoperatively, she developed sudden hypotension, bradycardia, dyspnea and disseminated intravascular coagulation (DIC), all signs associated with amniotic fluid embolism (AFE). Echocardiogram showed signs of acutely increased right ventricular after load including McConell's sign, i.e. right ventricular dilatation, segmental hypokinesia (mid-right ventricular) and hypercontractile right ventricular apex and overall right ventricular dysfunction. Similarly, 60/60 sign was positive on chocardiography (decreased right ventricular acceleration time of less than 60 milli-seconds and pulmonary artery systolic pressure of less than 60 mmHg). Performance of CT pulmonary angiogram failed to show any clear thromboembolic phenomenon; although, there were other indirect signs pointing towards the diagnosis. She was treated with aggressive supportive care without anticoagulation and she showed complete recovery, with follow-up echocardiogram becoming absolutely normal after 9 days with normalization of right ventricular size and function and improvement in 60/60 sign.

B-type natriuretic peptide and cardiac dysfunction in Duchenne muscular dystrophy.

Serum levels of B-type natriuretic peptide have moderate utility for detection of early ventricular dysfunction in adults and in experimental muscular dystrophy. To determine if B-type natriuretic peptide levels are useful in the detection of early left ventricular dysfunction in Duchenne muscular dystrophy patients, measurements were obtained in 21 patients being evaluated by echocardiography for left ventricular dysfunction. Two patients with clinical evidence of heart failure were excluded (mean B-type natriuretic peptide level of 352 pg/ml). Age range of the remaining 19 patients was 9-21 yrs. Fractional shortening was abnormal (<30%) in 14/19 and early diastolic tissue Doppler velocities were abnormal in 13/16. In these patients B-type natriuretic peptide levels were clearly normal (<30 pg/ml) in 15/19 and only mildly elevated (30-80 pg/ml) in 4/19. The 4 patients with mildly elevated B-type natriuretic peptide had significantly lower fractional shortening (12.6+/-5.9 versus 19.8+/-5.3, p<0.05). In conclusion, B-type natriuretic peptide levels are normal in the majority of Duchenne muscular dystrophy patients with asymptomatic left ventricular dysfunction and only mildly elevated when fractional shortening is markedly reduced.

Contribution of Doppler tissue imaging and myocardial performance index to assessment of left ventricular function in patients with Duchenne's muscular dystrophy.

Doppler tissue velocities (DTV) are abnormal in a variety of cardiac conditions when standard measures of ventricular function are normal. Detection of left ventricular dysfunction in Duchenne's muscular dystrophy (DMD) has relied on 2-dimensional imaging yet often these images are suboptimal. This study was undertaken to determine if DTV and the myocardial performance index (MPI) could provide additional diagnostic information in DMD. We determined in 31 patients and 13 age-matched control subjects the prevalence of both abnormal DTV of the mitral annulus and abnormal MPI. Mean values for early diastolic DTV were significantly lower for patients compared with control subjects (P < .001) and were abnormally low in 86% of patients. The MPI was abnormal in 79% of patients. All but one patient with DMD had either abnormal DTV or abnormal MPI yet 19% had normal fractional shortening. DTV and MPI are important additions to the echocardiographic evaluation of patients with DMD.