PubMed Health⌕ Search

Biomedical subjects

Jonathan Lessick

Publications and source records attributed to Jonathan Lessick.

18 recordsLinked to original sources
PubMed2006

Ischemic mitral regurgitation and risk of heart failure after myocardial infarction.

BACKGROUND: The development of ischemic mitral regurgitation (MR) after myocardial infarction may impose hemodynamic load during a period of active left ventricular remodeling and promote heart failure (HF). However, few data are available on the relationship between ischemic MR and the long-term risk for HF. METHODS: We prospectively studied 1190 patients admitted for acute myocardial infarction. Mitral regurgitation was assessed by echocardiography and was considered mild, moderate, and severe when the regurgitant jet area occupied less than 20%, 20% to 40%, and greater than 40% of the left atrial area, respectively. The median duration of follow-up was 24 months (range, 6-48 months). RESULTS: Mild and moderate or severe ischemic MR was present in 39.7% and 6.3% of patients, respectively. After adjusting for ejection fraction and clinical variables (age, sex, Killip class, previous infarction, hypertension, diabetes mellitus, anterior infarction, ST-elevation infarction, and coronary revascularization), compared with patients without MR, the hazard ratios for HF were 2.8 (95% confidence interval [CI], 1.8-4.2; P<.001) and 3.6 (95% CI, 2.0-6.4; P<.001) in patients with mild and moderate or severe ischemic MR, respectively. The adjusted hazard ratios for death were 1.2 (95% CI, 0.8-1.8; P = .43) and 2.0 (95% CI, 1.2-3.4; P = .02) in patients with mild and moderate or severe MR, respectively. CONCLUSIONS: There is a graded independent association between the severity of ischemic MR and the development of HF after myocardial infarction. Even mild ischemic MR is associated with an increase in the risk of HF.

Aged↗
PubMed2006

Accuracy of 16-row multidetector computed tomography for the assessment of coronary artery stenosis.

CONTEXT: Multidetector computed tomography (MDCT) has been proposed as a noninvasive method to evaluate coronary anatomy. OBJECTIVE: To determine the diagnostic accuracy of 16-row MDCT for the detection of obstructive coronary disease based exclusively on quantitative analysis and performed in a multicenter study. DESIGN, SETTING, AND PATIENTS: Eleven participating sites prospectively enrolled 238 patients who were clinically referred for nonemergency coronary angiography from June 2004 through March 2005. Following a low-dose MDCT scan to evaluate coronary artery calcium, 187 patients with an Agatston score of less than 600 underwent contrast-enhanced MDCT. Conventional angiography was performed 1 to 14 days after MDCT. Conventional angiographic and MDCT studies were analyzed by independent core laboratories. MAIN OUTCOME MEASURES: Segment-based and patient-based sensitivities and specificities for the detection of luminal stenosis of more than 50% (of luminal diameter) and more than 70% (of luminal diameter) based on quantitative coronary angiography. RESULTS: Of 1629 nonstented segments larger than 2 mm in diameter, there were 89 (5.5%) in 59 (32%) of 187 patients with stenosis of more than 50% by conventional angiography. Of the 1629 segments, 71% were evaluable on MDCT. After censoring all nonevaluable segments as positive, the sensitivity for detecting more than 50% luminal stenoses was 89%; specificity, 65%; positive predictive value, 13%; and negative predictive value, 99%. In a patient-based analysis, the sensitivity for detecting patients with at least 1 positive segment was 98%; specificity, 54%; positive predictive value, 50%; and negative predictive value, 99%. After censoring all nonevaluable segments as positive, the sensitivity for detecting more than 70% luminal stenoses was 94%; specificity, 67%; positive predictive value, 6%; and negative predictive value, 99%. In a patient-based analysis, the sensitivity for detecting patients with at least 1 positive segment was 94%; specificity, 51%; positive predictive value, 28%; and negative predictive value, 98%. CONCLUSIONS: The results of this study indicate that MDCT coronary angiography performed with 16-row scanners is limited by a high number of nonevaluable cases and a high false-positive rate. Thus, its routine implementation in clinical practice is not justified. Nevertheless, given its high sensitivity and negative predictive value, 16-row MDCT may be useful in excluding coronary disease in selected patients in whom a false-positive or inconclusive stress test result is suspected.

Adult↗
PubMed2006

Contrast enhanced multi-detector computed tomography coronary angiography versus conventional invasive quantitative coronary angiography in acute coronary syndrome patients-correlation and bias.

BACKGROUND: Previous studies that compared multi-detector computed tomography (MDCT) non-invasive coronary angiography with conventional coronary angiography, did not assessed the ability of MDCT to detect stenotic lesions correctly in acute coronary syndromes (ACS) patients. The aim of the present study was to assess prospectively the correlation and bias between 16-slice MDCT coronary angiography and quantitative coronary angiography analysis (QCA) in these patients. METHODS: Patients underwent electrocardiogram-gated, 16-slice MDCT coronary angiography and routine invasive percutaneous coronary angiography with quantitative coronary angiography (QCA) analysis blinded to MDCT results. The correlation and the bias between the results of MDCT and QCA were assessed in segments observed by both modalities in vessels > or = 2 mm in diameter. RESULTS: 59 patients (81% male, age 56 +/- 11 years), admitted due to ACS, underwent MDCT and invasive coronary angiography. 544 segments were analyzed. The correlations between MDCT and QCA observed for the left anterior descending coronary artery (LAD), the left circumflex coronary artery (Cx), the right coronary artery (RCA) and for all analyzed segments were 0.74 (P < 0.0001), 0.54 (P < 0.009), 0.72 (P < 0.0001) and 0.70 (P < 0.0001), respectively. By Bland-Altman analysis, a small overestimation of the lesion severity with MDCT of 4.8% for the LAD, 5.9% for the Cx, and 3.3% for the RCA was observed. CONCLUSIONS: In ACS patients, MDCT contrast-enhanced coronary angiography provides good quantification of the luminal diameter as compared to coronary angiography, and it is characterized by a small overestimation bias.

Angina, Unstable↗
PubMed2006

Multidetector-row computed tomography for noninvasive coronary imaging.

Computed tomography (CT) permits cross-sectional imaging of the heart. Temporal and spatial resolutions of the technique have been insufficient to cover the heart without motion artefacts until the recent advent of multidetector systems with more than 16 detector rows. The modality is now suited for noninvasive imaging of the coronary arteries, producing detailed morphologic images of the entire coronary tree with upto 0.4 mm of spatial resolution, within a single short breath-hold duration. CT imaging goes beyond the delineation of the coronary lumen as provided by selective invasive angiography; the plaque burden of the coronary artery wall can be visualized directly, utilizing soft-tissue contrast and a high sensitivity even for the small calcifications that are present in hard plaque formations. Therefore, CT combines elements of catheterization angiography for lumen imaging and of intravascular ultrasound imaging for coronary wall imaging. However current CT technology is not yet able to compete with the temporal or spatial resolution of catheterization angiography nor does it provide the detailed spatial or contrast resolution of intravascular ultrasound imaging. At present, its use is therefore restricted to complementing the invasive modalities in appropriate indications. Although CT entails significantly less risk than the invasive procedures, the risks of radiation dose exposure and contrast agent application are not negligible. In the foreseeable future, if the current rate of technological advancement continues, CT may replace the invasive modalities in routine care for diagnostic purposes.

Calcium↗
PubMed2006

16-MDCT coronary angiography versus invasive coronary angiography in acute chest pain syndrome: a blinded prospective study.

OBJECTIVE: The purpose of our study was to prospectively evaluate the usefulness of CT coronary angiography versus invasive coronary angiography for the detection of clinically significant coronary artery disease in patients hospitalized for acute chest pain syndrome. SUBJECTS AND METHODS: Sixty-six consecutive patients (52 men and 14 women; average age, 57 +/- 11 [SD] years) who were hospitalized for acute chest pain syndrome underwent CT coronary angiography and invasive coronary angiography within an average time interval of 4 days. ECG-gated CT coronary angiography was performed with a 16-MDCT scanner (0.42-sec rotation time, 16 x 0.75 mm detector collimation). Beta-blockers were not administered routinely, and thus the average heart rate was 71 +/- 11 beats per minute. CT coronary angiographic images were evaluated concurrently by two radiologists, who were blinded to invasive coronary angiography results, for stenoses having a diameter of 50% or more, using a 15-segment classification, including all segments 2 mm or more in diameter. The consensus interpretation was compared with results of invasive coronary angiography. RESULTS: CT coronary angiography was technically successful in 59 patients (89%). After exclusion of 20 (3.1%) of 649 coronary segments, which were classified as nonevaluable by CT coronary angiography, the sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of CT coronary angiography for identifying significant coronary artery disease in the remaining 629 coronary segments were 80% (68/85), 89% (482/544), 52% (68/130), 97% (482/499), and 87% (550/629), respectively. The overall accuracy for the main vessels (left main, left anterior descending, left circumflex, and right coronary arteries) was 93%, 88%, 86%, and 86%, respectively. CONCLUSION: CT coronary angiography using a 16-MDCT scanner enables accurate noninvasive detection of significant coronary artery disease in patients hospitalized for acute chest pain syndrome. Furthermore, relative high sensitivity and specificity of CT coronary angiography can be achieved without pharmacologic manipulation of patient heart rates.

Acute Disease↗
PubMed2005

Comparison of multidetector computed tomography versus echocardiography for assessing regional left ventricular function.

Multidetector computed tomography (MDCT) of the heart is a rapidly developing technique mainly used to evaluate the coronary arteries. However, it is also capable of evaluating ventricular function. It compares well with magnetic resonance imaging in calculating volumes and ejection fractions, but little has been reported on its ability to assess left ventricular (LV) segmental wall motion (LVSWM). This study compared semiquantitative LVSWM scoring by MDCT with echocardiography as the gold standard. Thirty-nine patients underwent MDCT angiography on a 16-slice scanner. Short- and long-axis LV slices were created at different phases of the cardiac cycle and visually evaluated using cine mode. Echocardiography was performed <48 hours after MDCT for 21 patients after acute myocardial infarctions and <1 month after MDCT for 18 patients without acute myocardial infarctions. Two blinded observers scored the MDCT and echocardiographic examinations according to the 16-segment model, scoring each segment from 1 (normal) to 3 (akinetic). Segmental dysfunction was found in 27 patients by echocardiography and in 24 by MDCT. An identical score was given by the 2 methods in 502 of 616 assessable segments (82%). Using a binary analysis (normal or abnormal), there was 89% agreement (546 of 616 segments). MDCT had a sensitivity of 66% (103 of 155 segments) and a specificity of 96% (443 of 461 segments) compared with echocardiography as the gold standard. Most disagreements occurred in the right coronary artery segments. In conclusion, MDCT can be used to evaluate LVSWM, showing good agreement with echocardiography, except for the right coronary artery segments.

Adult↗
PubMed2005

Automatic determination of minimal cardiac motion phases for computed tomography imaging: initial experience.

Low motion phases for cardiac computed tomography reconstructions are currently detected manually in a user-dependent selection process which is often time consuming and suboptimal. The concept of motion maps was recently introduced to achieve automatic phase selection. This pilot study compared the accuracy of motion-map phase selection to that with manual iterative selection. The study included 20 patients, consisting of one group with low and one with high heart rate. The technique automatically derives a motion strength function between multiple low-resolution reconstructions through the cardiac cycle, with periods of lowest difference between neighboring phases indicating minimal cardiac motion. A high level of agreement was found for phase selection achieved with the motion map approach compared with the manual iterative selection process. The motion maps allowed automated quiescent phase detection of the cardiac cycle in 85% of cases, with best results at low heart rates and for the left coronary artery. They can also provide additional information such as the presence of breathing artifacts. Motion maps show promise as a rapid off-line tool to automatically detect quiescent cardiac phases in a variety of patients.

Adult↗
PubMed2005

Clinical value of 16-slice multi-detector CT compared to invasive coronary angiography.

BACKGROUND: Multi-detector row spiral CT (MDCT) can be applied as a noninvasive tool for the assessment of coronary artery stenoses. Few, confounding reports have been published using 16 detector rows. The aim of the present study was to determine the accuracy of 16-detector row MDCT for the detection of significant stenoses in the coronary arteries, in comparison to conventional invasive coronary angiography. METHODS: Twenty-two patients with suspected coronary artery disease, were prospectively evaluated by 16-slice retrospectively ECG-gated CT coronary angiography and quantitative invasive coronary angiography. The findings were compared for the detection of significant coronary artery stenoses (>50%) in all segments with diameter >1.5 mm. RESULTS: MDCT correctly classified all 14 patients (100%) that were found to have significant coronary artery disease on conventional angiography. Overall, 288 segments were included in the analysis, regardless of their image quality. Significant stenoses were detected in 24 segments by CT and in 28 segments by conventional angiography. Out of 260 segments that were negative for significant stenoses on conventional angiography, 255 were correctly identified on CT. The sensitivity, specificity, positive and negative predictive values were 86, 98, 83 and 98%, respectively. MDCT also revealed supplementary findings that invasive angiography was unable to visualize, including anomalous vessel course, the course of vessels filling via collaterals, intramyocardial course of vessels and non-stenotic plaques. CONCLUSIONS: MDCT coronary angiography utilizing 16-detector rows shows promising results for reliable detection of coronary artery stenoses and particularly for ruling out significant disease.

Adult↗
PubMed2004

Global longitudinal strain: a novel index of left ventricular systolic function.

BACKGROUND: Echocardiographic estimation of global left ventricular (LV) function is subjective and time consuming. Our aim was to develop a novel approach for assessment of global LV function from 2-dimensional echocardiographic images METHODS: Novel computer software for tissue tracking was developed and applied as follows: digital loops were acquired from apical 2-, 3-, and 4-chamber views and a line was loosely traced along the LV endocardium at the frame wherein it was best defined. Around this line, the software selected natural acoustic markers moving with the tissue. Automatic frame-by-frame tracking of these markers during the heart cycle yielded a measure of contractility along the selected region of interest. Global longitudinal strain (GLS) and GLS rate (GLSR) were calculated for the entire U-shaped length of LV myocardium (basal, mid, and apical segments of 2 opposite walls in each view). To test this software, computer-derived GLS and GLSR were analyzed by a nonechocardiographer, blinded to the echocardiographic interpretation, in 27 consecutive patients after myocardial infarction (MI) (age 64.4 +/- 12.9 years; 19 men; mean wall-motion score index of 1.79 +/- 0.44) and compared with those obtained in 12 consecutive control patients (age 59.0 +/- 9.7 years; 8 women), with a normal echocardiographic study. RESULTS: GLS and GLSR, averaged from the 3 apical views, differed significantly in patients post-MI compared with control patients (GLS -14.7 +/- 5.1% vs -24.1 +/- 2.9% and GLSR -0.57 +/- 0.21/s vs -1.02 +/- 0.09/s for patients post-MI vs control patients, respectively; both P <.0001). There was a good linear correlation between the wall-motion score index and the GLS and GLSR (R = 0.68 and R = 0.67, respectively; both P <.0001). A cut-off value for GLS of -21% had 92% sensitivity and 89% specificity and a cut-off value for GLSR -0.9/s had 92% sensitivity and 96% specificity for the detection of patients post-MI. CONCLUSIONS: GLS and GLSR are novel indices for assessment of global LV function from 2-dimensional echocardiographic images. Early validation studies with the method are suggestive of high sensitivity and specificity in the detection of LV systolic dysfunction in patients post-MI.

Adult↗
PubMed2003

Natural history of moderate mitral valve stenosis.

BACKGROUND: With the introduction of surgery and percutaneous balloon valvuloplasty for relieving severe mitral stenosis the natural history of the disease has markedly altered. OBJECTIVES: To determine the natural history of the disease in patients with moderate mitral valve stenosis. METHODS: Demographic, clinical and echocardiographic data were evaluated in 36 patients with moderate mitral stenosis during a follow-up of 71 +/- 15 months. RESULTS: The 36 patients comprised 32 women and 4 men with a mean age of 43.7 +/- 12.2 years; 28 were Jewish and 8 were of Arab origin. During follow-up, there was a significant decrease in mitral valve area, with an increase in mean mitral valve gradient and score. Mean loss of mitral valve area was 0.04 +/- 0.11 cm 2/year. No correlation was found between disease progression and age, past mitral valve commissurotomy, baseline mean gradient or mitral valve score. Larger baseline mitral valve area (P = 0.007) and Arab origin (P = 0.03) had an independent correlation to loss of mitral valve area. Fifteen patients (42%) did not demonstrate any loss in mitral valve area during the follow-up period. CONCLUSIONS: The rate of mitral valve narrowing in patients with moderate mitral stenosis is variable and cannot be predicted by patient's age, past commissurotomy, valve score or gradient. Secondly, larger baseline mitral valve area and Arab origin showed an independent correlation to loss of mitral valve area; and finally, in many patients valve area did not change over a long observation period.

Adult↗
PubMed2002

Temporal changes in the endocardial ST segment during the evolution of myocardial infarction in dogs.

Acute coronary occlusion causes ST-segment elevation on the body surface ECG and on the epicardial electrogram in the territory supplied by that artery. The occurrence and significance of endocardial ST changes have not been studied. The NOGA electromechanical mapping was performed on eight anesthetized dogs at baseline, immediately after occlusion of the LAD, and again at 5 hours to assess regional changes in the ST segment. At 3 days and 4 weeks the ventricles were remapped for comparison. Regional unipolar ST-segment elevation was measured for each zone from NOGA maps at 0, 80, and 120 ms after the J point. ST segments rose immediately in the infarct zones, as demarcated by echocardiography, compared to remote zones, but by 3 days had dropped below, and at 4 weeks returned to baseline values. Immediately postocclusion, ST elevation at 120 ms best differentiated between normal versus abnormal echo scores (concordance = 0.80), probably by correcting for pressure induced ST elevation. In conclusion, acute endocardial ST-segment changes occur in the infarct zone in the dog, showing a distinctive temporal evolution.

Animals↗
PubMed2002

Failure of left ventricular hypertrophy to regress after surgery for aortic valve stenosis.

BACKGROUND: Regression of left ventricular (LV) hypertrophy usually follows surgery for aortic stenosis (AS); however, a significant number of ventricles remain hypertrophied. The extent of this phenomenon, the reasons for failure to regress, and its significance are unclear. METHODS: We investigated 43 patients before and after aortic valve surgery and divided them into two groups: 30 patients with regression of LV hypertrophy (Group A) and 13 patients without regression (Group B). Preoperative echocardiographic measurements, clinical status, and operative factors were compared between the two groups. The patients were followed up for 42 +/- 22 months for the occurrence of hospitalization for congestive heart failure (CHF) or death. RESULTS: Preoperatively, the two groups were similar except for an excess of patients in New York Heart Association (NYHA) functional Class IV and a greater incidence of old myocardial infarcts in Group B. Postoperatively, Group B patients had larger LVs with decreased systolic function. This was associated with a poor prognosis (23% mortality and 38% CHF vs 0% and 4% for Group A patients, P = 0.0002). Cox regression analysis showed previous myocardial infarction (P < 0.001) and percent mass reduction (P = 0.019) to be independent predictors of CHF or death. CONCLUSIONS: Successful regression of LV mass is difficult to predict before surgery; however, its absence is related strongly to a poor long-term prognosis.

Aged↗
PubMed2002

Evaluation of inotropic changes in ventricular function by NOGA mapping: comparison with echocardiography.

Assessment of left ventricular (LV) function in the catheterization laboratory is important to optimize treatment decisions and guide catheter-based local therapies. NOGA electromechanical mapping was developed to assess LV contraction during catheterization; however, quantitative analysis of its "local shortening" (LS) algorithm and direct comparison with conventional methods are lacking. We evaluated the accuracy of NOGA-based regional and global function by examining its ability to detect pharmacologically induced changes in contractility compared with echocardiography. Ten anesthetized pigs were paced to ensure a constant heart rate throughout the experiment. Electromechanical maps of the LV and short-axis echocardiograms were obtained 1) at baseline, 2) during intravenous dobutamine, and 3) after intravenous propranolol. NOGA LS and ejection fraction (EF) consistently increased under dobutamine and decreased after propranolol. NOGA LS and NOGA and echocardiography circumferential shortening correlated highly with one another (r > 0.80), as did NOGA EF with echocardiography EF (r = 0.92), although absolute values differed somewhat. Thus NOGA-based global and regional function correlates closely with echocardiography and is sensitive to changes in contractility, but, at the upper end of the scale, LV function is underestimated.

Animals↗
PubMedDate not supplied

Anomalous origin of right coronary artery: diagnosis and dynamic evaluation with multidetector computed tomography.

16 slice multidetector CT findings of an anomalous right coronary artery originating from the left sinus of Valsalva are presented. Multidetector CT depicted the malignant coronary anomaly in great anatomic detail as well as enabled dynamic evaluation through the cardiac cycle, documenting a substantial reduction in arterial diameter during peak systole. This case illustrates the full capabilities of multidetector cardiac CT in the evaluation of coronary artery pathology.

Coronary Vessel Anomalies↗
PubMedDate not supplied

Anomalous origin of a posterior descending artery from the right pulmonary artery: report of a rare case diagnosed by multidetector computed tomography angiography.

The case of a mildly symptomatic 43-year-old man with evidence of reversible inferior wall ischemia by radioisotope stress testing is described. Invasive catheterization showed abnormal connections between the coronary arteries and the pulmonary circulation. Multidetector computed tomography elucidated the previously undescribed finding of a posterior descending artery originating from the right pulmonary artery.

Adult↗
PubMedDate not supplied

Septal bounce in constrictive pericarditis. Diagnosis and dynamic evaluation with multidetector CT.

Sixteen-slice multidetector CT findings of a case of constrictive pericarditis in a pediatric patient are presented. Multidetector CT depicted a variety of diagnostic findings including dynamic evaluation of interventricular septal motion through the cardiac cycle, documenting a diastolic septal bounce. This case illustrates the full capabilities of multidetector cardiac CT in the evaluation of pericardial pathology.

Adolescent↗
PubMedDate not supplied

Comprehensive multidetector computed tomography assessment of severe cardiac contusion in a pediatric patient: correlation with echocardiography.

Multidetector computed tomography (MDCT) cardiac findings in an unconscious teenager after blunt chest trauma are presented. Multidetector computed tomography enabled accurate comprehensive evaluation of the coronary arteries, myocardial perfusion, and left ventricular function. This case illustrates the full capabilities of MDCT in the evaluation of cardiac contusion in a noncooperative pediatric patient.

Adolescent↗