This Article Full Text (PDF) References Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Add to Saved Citations Download to citation manager Request Permissions Request Reprints Add to My Marked Citations Citing Articles Citing Articles via Google Scholar Citing Articles via Scopus Google Scholar Articles by Pontillo, D. Articles by Guerra, R. Search for Related Content PubMed PubMed Citation Articles by Pontillo, D. Articles by Guerra, R. Pubmed/NCBI databases Compound via MeSH Substance via MeSH Medline Plus Health Information Heart Attack Hazardous Substances DB NITROGLYCERIN THALLIUM, ELEMENTAL Social Bookmarking                         What's this?

Identification of Viable Myocardium by Nitrate Echocardiography After Myocardial Infarction: Comparison with Planar Thallium Reinjection Scintigraphy

Cardiology Division, Belcolle Hospital, Viterbo

Gian Piero Carboni

Nuclear Cardiology Section, Villa del Rosario Clinic, Rome, Italy

Aldo Capezzuto

Cardiology Division, Belcolle Hospital, Viterbo

Claudio Alessi

Cardiology Division, Belcolle Hospital, Viterbo

Augusto Achilli

Cardiology Division, Belcolle Hospital, Viterbo

Francesca Piccini

Cardiology Division, Belcolle Hospital, Viterbo

Roberto Guerra

Cardiology Division, Belcolle Hospital, Viterbo

Background: The aim of this study was to validate a new diagnostic tool, nitrate echocar diography (NE), for the identification of viable noncontracting myocardium in patients with a history of prior myocardial infarction (MI). Nitroglycerin (NTG) may be useful for this purpose for its peculiar pharmacodynamic action and may represent an option other than dobutamine echocardiography for the detection of hibernating segments in the presence of severely reduced coronary reserve.

Methods: Twenty selected patients (pts) with an old MI were studied with NE and planar thallium scintigraphy with reinjection. NE was performed by administering IV NTG starting at 0.4 mcg/kg/minute with equal increments every five minutes up to 2 mcg/kg/minute or to early interruption of the test (decrease of systolic blood pressure 20% or improvement of previously akinetic segments). Left ventricular wall motion was analyzed by dividing the left ventricle (LV) into 16 segments, and a wall motion score index (WMSI) was calculated. Thallium images were obtained at peak exercise, at four hours, and after reinjection. Myocardial viability was defined as an improvement in thallium uptake after reinjection in fixed defects. (continued on next page)

Results: Basal echo demonstrated 74 akinetic segments; of these 21 (28%, 11 pts) showed improved contractility during NTG infusion at a mean dose of 0.87 ±0.33 mcg/kg/minute. WMSI decreased from 1.69 ±0.29 to 1.46 ±0.31 (P=.001). The only hemodynamic response was a drop in systolic blood pressure (136 mmHg to 124; P=.02). Thallium studies showed 29 segments with a four-hour reversible defect and 79 segments with a four-hour fixed defect; of the latter, 14 regions demonstrated improvement in tracer uptake after reinjection (17.7%; 10 pts). Nine pts had a positive echo and thallium study, while 8 showed no improvement either during NE or after thallium reinjection. Two pts had a false-positive nitrate echocardiogram. Therefore, according to an echo/thallium study match, sensitivity, specificity, and accuracy are 90%, 80%, 85%, respectively.

Conclusion: NE is a reliable and low-cost method for the detection of viable noncon tracting myocardium in selected patients with CAD but needs further validation for wide spread application.

Angiology, Vol. 47, No. 5, 437-446 (1996)
DOI: 10.1177/000331979604700502


CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    Twitter    What's this?