title: Transthoracic Doppler echocardiography to noninvasively assess coronary vasoconstrictor and dilator responses in humans.
abstract: Human studies of coronary circulation are limited because of methodological issues. Recently, a noninvasive transthoracic duplex ultrasound (TTD) technique has emerged as an important tool to measure coronary blood flow velocity (CBV) in conscious humans. We employed two protocols to determine whether noninvasive "native" coronary artery velocity responses to constrictor or dilator stimuli assessed by TTD provide reliable data. In the first protocol, coronary vascular resistance (CVR = diastolic blood pressure/CBV) responses to static handgrip were examined in the left internal mammary artery (LIMA) and native left anterior descending artery (LAD) into which the graft was inserted (patient age 63 +/- 3 years). Our prior report documented increased CVR in the LIMA graft during static handgrip (Momen et al., J Appl Physiol 102: 735-739, 2007). We hypothesized that the magnitude of increases in CVR during handgrip would be similar in the LIMA graft and LAD in the same individual. Percent increases in CVR were similar in the LIMA and distal native LAD (27 +/- 4% vs. 28 +/- 6%). In the second protocol, we studied six patients (age 61 +/- 3 years) who underwent cardiac catheterization of the LAD. We compared coronary vasodilator responses to intravenous adenosine infusion (0.14 mg.kg(-1).min(-1)) obtained by intracoronary Doppler guidewire technique and TTD on separate studies. The relative increases in CBV with adenosine obtained by intracoronary Doppler guidewire and TTD were similar (62 +/- 10% vs. 65 +/- 12%). Noninvasive TTD provides reliable human coronary circulatory constrictor and dilator data.
authors: Penn State Heart & Vascular Institute, The Pennsylvania State University College of Medicine, The Milton S. HersheyMedical Center, Hershey, Pennsylvania, USA.
authors: Afsana
authors: A
authors: Momen
authors: Mark
authors: M
authors: Kozak
authors: Urs A
authors: UA
authors: Leuenberger
authors: Steven
authors: S
authors: Ettinger
authors: Cheryl
authors: C
authors: Blaha
authors: Vernon
authors: V
authors: Mascarenhas
authors: Vasili
authors: V
authors: Lendel
authors: Michael D
authors: MD
authors: Herr
authors: Lawrence I
authors: LI
authors: Sinoway
mesh_terms: D000241:Adenosine / Q000494:pharmacology; D000368:Aged; D001783:Blood Flow Velocity / Q000187:drug effects / Q000502:physiology; D001794:Blood Pressure / Q000187:drug effects; D006328:Cardiac Catheterization; D001026:Coronary Artery Bypass; D003331:Coronary Vessels / Q000000981:diagnostic imaging* / Q000502:physiology*; D004452:Echocardiography; D005260:Female; D018737:Hand Strength / Q000502:physiology; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D008297:Male; D008323:Mammary Arteries / Q000000981:diagnostic imaging / Q000502:physiology; D008875:Middle Aged; D012039:Regional Blood Flow / Q000187:drug effects / Q000502:physiology; D014655:Vascular Resistance / Q000187:drug effects / Q000502:physiology*; D014661:Vasoconstriction / Q000502:physiology*; D014664:Vasodilation / Q000187:drug effects / Q000502:physiology*; D014665:Vasodilator Agents / Q000494:pharmacology
chemical_list: D014665:Vasodilator Agents; D000241:Adenosine