Doppler ultrasound examination was performed in 69 patients with a variety of cardiopulmonary disorders who were undergoing bedside right heart catheterization. Patients were classified into two groups on the basis of hemodynamic findings. Group I consisted of 20 patients whose pulmonary artery systolic pressure was less than 35 mm Hg and Group II consisted of 49 patients whose pulmonary artery systolic pressure was 35 mm Hg or greater. Tricuspid regurgitation was detected by Doppler ultrasound in 2 of 20 Group I patients and 39 of 49 Group II patients (p less than 0.001). Twenty-six of 27 patients with pulmonary artery systolic pressure greater than 50 mm Hg had Doppler evidence of tricuspid regurgitation. In patients with tricuspid regurgitation, continuous wave Doppler ultrasound was used to measure the velocity of the regurgitant jet, and by applying the Bernoulli equation, the peak pressure gradient between the right ventricle and right atrium was calculated. There was a close correlation between the Doppler gradient and the pulmonary artery systolic pressure measured by cardiac catheterization (r = 0.97, standard error of the estimate = 4.9 mm Hg). Estimating the right atrial pressure clinically and adding it to the Doppler-determined right ventricular to right atrial pressure gradient was not necessary to achieve accurate results. These findings indicate that tricuspid regurgitation can be identified by Doppler ultrasound in a large proportion of patients with pulmonary hypertension, especially when the pulmonary artery pressure exceeds 50 mm Hg. Calculation of the right ventricular to right atrial pressure gradient in these patients provides an accurate noninvasive estimate of pulmonary artery systolic pressure.
To assess the prevalence and flow characteristics of valvular regurgitation detected by Doppler echocardiography in normal subjects, pulsed and continuous wave Doppler studies were performed in 100 adult volunteers without evidence of heart disease. Evidence of valvular regurgitation was present in 73% of subjects. There were 46 subjects with regurgitation of one valve, 24 with regurgitation of two valves and 3 with regurgitation of three valves. Right-sided regurgitation was significantly more common than was left-sided regurgitation (81 versus 22 valves, p less than 0.01). Regurgitant flow was never detected farther than 1 cm from the valve by pulsed Doppler study. Tricuspid regurgitation was detected in 50 subjects and was characterized by a holosystolic velocity signal; a complete spectral envelope was recorded in 32 subjects. The peak velocity of the regurgitant jet for this group was 1.7 to 2.3 m/s (mean 2.0 +/- 0.2). Thirty-one subjects were found to have pulmonary regurgitation with a peak velocity of 1.2 to 1.9 m/s (mean 1.5 +/- 0.2); no subject demonstrated regurgitant flow in early diastole. There were 21 subjects with mitral regurgitation; continuous wave Doppler signals were always of low intensity with a poorly defined spectral envelope and an absence of high velocities. Peak velocities ranged from 1.1 to 4.4 m/s (mean 2.3 +/- 0.9) and in 19 subjects were less than 3.5 m/s. The mean age of subjects with mitral regurgitation was significantly higher than that of subjects without mitral regurgitation (p = 0.01). Aortic regurgitation was detected in only one subject. This study provides further evidence that valvular regurgitation is frequently detected by Doppler echocardiography in normal subjects.(ABSTRACT TRUNCATED AT 250 WORDS)
Blood-pool (BP)-gated SPECT should be able to detect regional left ventricular (LV) dysfunction, as the modality is fully 3-dimensional and capable of resolving all cardiac chambers. This study investigates the hypothesis that LV segments that have abnormal regional wall motion (WM) on a cardiac MRI scan also have abnormal BP regional ejection fraction (EF) as computed by fully automated quantitation (AQ) of BP data. Methods: A total of 34 patients evaluated for coronary artery disease who underwent visual assessment of WM by review of BP cines and cardiac MRI evaluations were included in this retrospective investigation. Cardiac MRI values for these patients were compared with an institutional database of cardiac MRI values for an age-matched cohort of 10 healthy volunteers. An AQ algorithm segmented the LV BPs on the BP tomograms and subdivided volumes into 17 subregions. Count-versus-time curves were fit to third-order Fourier series for each LV subvolume to compute regional EFs. For cardiac MRI data, endocardial and epicardial drawings were performed manually for 60°sam-ples of 11-13 short-axis tomograms spanning the entire heart, from which regional WM values were computed and rebinned into 17 conventional LV segments. Results: Global EF ranged from 12% to 75% on AQ and from 14% to 75% on cardiac MRI (Pearson correlation coefficient 5 0.95, P , 0.0001). Differences were not significant between BP AQ and cardiac MRI in identifying the 12 patients with a global EF less than 35% (McNemar difference, 3%; P 5 1.0) and the 19 patients with an EF less than 50% (difference, 3%; P 5 1.0). BP AQ was more accurate than was visual assessment for identifying LV segments with abnormal cardiac MRI WM (receiver-operating-characteristic areas, 88% vs. 80%, P , 0.0001) and was more accurate for the left circumflex than for the left anterior descending coronary artery territories (95% vs. 86%, P 5 0.01). Differences were not significant between BP AQ and cardiac MRI WM for discriminating normal from abnormal LV segments (McNemar difference, 3.2%; P 5 0.14). Conclusion: AQ BP-gated SPECT assessment of regional and global LV WM agrees with independent cardiac MRI calculations and is superior to visual analysis for detecting regional WM abnormalities.
Noninvasive cardiac imaging plays a central role in the diagnosis of coronary artery disease and cardiomyopathy, as well as in the decision making for therapeutic interventions. Proper assessment of the degree of myocardial ischemia and viability is essential to aid in therapies that may improve patient outcomes. In addition, a wealth of evidence exists on the prognostic value of the information obtained from noninvasive imaging. One must utilize an imaging study or studies in an organized fashion, incorporating the latest scientific evidence, guidelines and appropriateness criteria. This review summarizes the advantages, disadvantages and relevant literature on various imaging modalities currently available for the evaluation of myocardial ischemia and viability.
Purpose Computations of left and right ventricular (LV and RV) gated blood pool SPECT (GBPS) ejection fraction (EF) have been well validated against other imaging modalities. As GBPS images depict the entire extent of both blood pools, it is possible to compute not only global but also regional biventricular function parameters, which have the prospect of being clinically useful for planning cardiac resynchronization therapy. This investigation sought to establish LV and RV count-based GBPS regional functional normal limits and to quantify their reproducibility. Methods and materials Count-versus-time curves were fit to third-order Fourier series for each of 17 LV and RV sub-volumes to compute global and regional EF, timing, phase and dyssynchrony parameters. Algorithms were applied to data for 40 normal controls (NLs) and 15 patients with CHF. To assess reproducibility, data were reprocessed a second time, blinded to initial calculations. Results There were no statistically significant differences between any initial and reprocessed LV or RV parameters for NLs or patients with CHF. Percent of subjects categorized as abnormal were the same for initial and reprocessed parameters (McNemar's differences = 0-7%, P [ 0.05 for each parameter). Most parameters were significantly different for patients with CHF versus NLs. Normal limits for the new technique agreed well with the literature for other imaging methods, and RV normal limits closely paralleled LV limits. Conclusion GBPS global and regional LV and RV normal limits are reproducible, and application of these normal limits to patients with CHF results in reproducible detection of functional abnormalities.
Smoking is a major modifiable risk factor for cardiovascular (CV) disease. Varenicline is a pharmacological aid for smoking cessation. To explore the CV safety of varenicline, we investigated the incidence of CV events in varenicline-treated subjects across all phase 2-4 randomized placebo-controlled clinical trials of ≥12-week treatment duration conducted in smokers aged ≥18 years and sponsored by the drug manufacturer. This manuscript reports a subject-level meta-analysis of time to major adverse cardiovascular events (MACE; defined as CV-related death, nonfatal myocardial infarction, nonfatal stroke) and time to MACE+ (defined as MACE plus worsening or any procedure for peripheral vascular disease, hospitalization for angina, or performance of coronary revascularization). All events were adjudicated by an independent adjudication committee, blind to treatment assignment. Events were assessed during treatment and up to 30 days after the last treatment dose. The primary analytical method was a stratified logrank time-to-event analysis; secondary analyses were meta-analyses of incidence rate ratios and rate differences. Overall, 7002 subjects were included (varenicline: 4190; placebo: 2812) from 15 studies. MACE were reported by 13 varenicline subjects (0.31%) and 6 placebo subjects (0.21%) [hazard ratio, 1.95; 95% confidence interval (CI): 0.79-4.82; P = 0.15; risk difference, 0.006 events per subject-year; 95% CI: -0.003, 0.015, P = 0.19]. MACE+ were reported by 26 varenicline subjects (0.62%) and 12 placebo subjects (0.43%) (hazard ratio, 1.74; 95% CI: 0.91-3.34, P = 0.10; risk difference, 0.010; 95% CI: -0.002, 0.022, P = 0.11). This subject-level meta-analysis of MACE or MACE+ up to 30 days posttreatment in placebo-controlled clinical trials of varenicline found a trend toward increased incidence of these events in varenicline-treated patients that did not reach statistical significance. The overall number of events was low and the absolute risk of CV events with varenicline was small.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.