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???? Basic Veterinary Echocardiography The Subject for a Radiologist? Daniel A. Feeney DVM, MS Professor of Veterinary Radiology College of Veterinary Medicine University of Minnesota Transducer Configuration What is Echocardiography? • High Hz Sound – TRANSMITTED – REFLECTED – TRANSLATED into time-associated image (graphic 2-D) Goals of Current Discussion • COMPARE Echocardiography to Survey & Contrast Radiography • Introduce BASIC Technical Aspects of Echocardiography • Introduce ELEMENTARY Interpretive Principles of Echocardiography • Focus on Diagnoses for the GENERALIST • Radiologist doing echocardiography = plumber doing neurosurgery? Justification for Echocardiography • Shortcomings of Survey Radiography – – – – – – hypertrophy vs. dilation no information cardiac function no information on valves no information on internal cardiac anatomy miss masses (pericardial sac or heart) pleural fluid problems Justification for Echocardiography Justification for Echocardiography • Shortcomings of Contrast Radiography (particularly angiography) • Shortcomings of Contrast Radiography (particularly angiography) – contrast media risk – nonselective angiography +/- for shunts – selective angiography invasive anesthesia risk specialized equipment – pericardial sac procedures (e.g. pneumopericardiogram) invasive anesthesia risk embolism & hemorrhage risk Justification for Echocardiography Applications of Echocardiography • • • • • • noninvasive no contrast media risk sector scanners applicable for general abdomen, etc. hypertrophy vs. dilation quantitate cardiac function find masses in the pericardial sac or heart (not 100%) • no pleural fluid problems • information on internal cardiac anatomy & valves • determine size and quantitate function of cardiac chambers • identify intracardiac or pericardial sac masses (or vegetations) • non-invasively reevaluate indices of cardiac function after Rx • clarify origin of pleural fluid Technical Considerations Technical Considerations • Windows – [R, 4-5] parasternal intercostal (M-mode standard) – [L, 3-4] cranial parasternal intercostal – [L, 5-6] caudal parasternal intercostal (apical) • Transducer Configuration/Frequency (Hz) – “inline” configuration – Use Hz that will put area of interest in focal zone of transducer horses/cattle 2.25-3.5 MHz medium/large dogs 3.5-5.0 MHz small dogs/cats 5.0-7.5 MHz Technical Considerations Cardiac Notch • Cardiac Anatomy vs. Ultrasound Display Modes/Views From: Boon J, Wingfield WE & Miller Cw: Echocardiographic Indices in the Normal Dog. Vet Radiol 24:214-221, 1983. M-mode Real-time, sector, 2D* * Two-dimensional Views Technical Considerations R parasternal long axis R parasternal short axis L (cranial parasternal long axis L (caudal) [apical] parasternal long axis L parasternal short axis Anatomy • Cardiac Anatomy vs. Ultrasound Display Modes/Views – “M-mode easiest method by which to obtain cardiac dimension.” – “The 2-D is generally superior in identification of cardiac masses, atrioventricular septal defects, regional wall disorders and heartworms.” (Bonagura, O’Grady & Herring: VCNA(SA) 15:1177, 1985) Anatomy Basics of Interpretation • What Parts Have You Identified (is the study complete)? – Valves aortic semilunar (M-mode & 2-D) mitral (M-mode & 2-D) pulmonic (2-D) tricuspid (M-mode & 2-D) [BEST-LCrP/S L-A or LCrP/S S-A] Basics of Interpretation • What Parts Have You Identified (is the study complete)? – Chambers left atrium (M-mode & 2-D) left ventricle (M-mode & 2-D) right ventricle (M-mode & 2-D) right atrium (2-D) [BEST-LCaP/S L-A (apical) view] Technical Considerations Basics of Interpretation • What Parts Have You Identified (is the study complete)? – Miscellaneous Structures chordae tendinae (M-mode & 2-D) pericardium (M-mode & 2-D) papillary muscles (M-mode & 2-D) endocardium (M-mode & 2-D) Making Sense of M-mode • Contrast Echocardiography – Use of saline, green dyes, aggregated albumen, etc. to create echogenic fluid or bubbles which will flow with the blood and identify its course – Use for identifying shunts From: Feigenbaum H: Echocardiography (3rd edition) Lea & Febiger, Philadelphia, 1981. Long-axis, RL From: Thomas WP: Two-dimensional, Real-time Echocardiography in the Dog – Technique & Anatomic Validation. Vet Radiol 25:50-64, 1984 Long-axis, RL From: Thomas WP: Two-dimensional, Real-time Echocardiography in the Dog – Technique & Anatomic Validation. Vet Radiol 25:50-64, 1984 Long-axis, RL Doppler: Duplex/Color-flow RL Long Axis (loop) Short-axis, RL From: Thomas WP: Two-dimensional, Real-time Echocardiography in the Dog – Technique & Anatomic Validation. Vet Radiol 25:50-64, 1984 Short-axis, RL From: Thomas WP: Two-dimensional, Real-time Echocardiography in the Dog – Technique & Anatomic Validation. Vet Radiol 25:50-64, 1984 Short-axis, RL From: Thomas WP: Two-dimensional, Real-time Echocardiography in the Dog – Technique & Anatomic Validation. Vet Radiol 25:50-64, 1984 Short-axis, RL 4-chamber, LR/M-mode, RL 4-chamber, LR Basics of Interpretation • Are These Structures Basically Normal? – – – – – ? chambers conspicuously dilated or compromised ? contractility = 30%, rate & rhythm ? any percardial fluid [vs. pleural fluid] ? any masses or vegetations ? CVC persistently dilated, 4-5 level hepatic vein branches seen – ? obvious spontaneous contrast in the chambers Basics of Interpretation • On Further Practical Scrutiny, Are They Sill Normal? – ? is ECG normal – ? is mitral valve motion normal [AMV = “M”] – ? paradoxical septal motion Basics of Interpretation • On Further Practical Scrutiny, Are They Sill Normal? – Relevant Generalities • right ventricular free wall = 1/3-1/2 as thick as ventricular free wall in small animals (Bonagura, Herring: VCNA(SA) 15:1195, 1985) • excessive “E-point” [1st hump of AMV’s “M”] to septal separation consider left ventricular dilation or failure (Bonagura, O’Grady & Herring: VCNA(SA) 15:1208, 1985) Basics of Interpretation • Relevant Referenced Normal Parameters By Species – Dog-many dimensions proportional to body size1 – Cat-only weak relationship between dimensions & body size2 – Horse-most dimensions not specified as varying with breed/size3 1 2 3 Basics of Interpretation • Relevant Referenced Normal Parameters By Species – “There is good agreement between 2-D & M’moade indices of heart size except for the left atrial side, whick is measurably larger within 2/d.”4 4 Bonagura, Herring: VCNA(SA) 15:1995, 1985 Bonagura, O’Grady & Herring: VCNA(SA) 15:1208, 1985 Boon, Wingfield & Miller: Vet Radiol 24:214, 1983 O’Grady, Bonagura, Powers & Herring: Vet Radiol 27:34, 1986 Bonagura, O’Grady & Herring: VCNA(SA) 15:1208, 1985 Bonagura, Herring & Welker: VCNA(SA) 2:311, 1985 Basics of Interpretation Canine Measurement Scheme • Measurement Standardization that used for humans: Sahn DJ, DeMaria A, Kisslo J, et.al.: Circulation 58:1072-1083, 1978. [M-mode Echocardiography] Henery WL, DeMaria A, Gramiak R, et.al.: Circulation 62:212-217, 1980 [2-D Echocardiography] – Leading edge method – Systolic measurements “nadir of septal motion” – Diastolic measurements “onset of the QRS complex” Boon J, Wingfild WE & Miller CW: Echocardiographic Indices in the Normal Dog Vet Radiol 24:214-221, 1983 Canine Measurement Scheme Bonagura JD, O’Grady MR & Herring DS: Echocardiography – Principles of Interpretation Vet Clin North Am (SA) 15:1177-1194, 1985 Canine Dilatory Cardiomyopathy Canine Dilatory Cardiomyopathy Canine Dilatory Cardiomyopathy & L Atrial Clot Feline Hypertrophic Cardiomyopathy Feline Hypertrophic Cardiomyopathy Feline Dilatory Cardiomyopathy Feline Dilatory Cardiomyopathy Pericardial Infusion Bullet Pericardial Infusion Bullet Pericardial Fluid + Masses (clots) Endocarditis (cow) Heartbase Mass Heartbase Mass Mitral Endocardiosis fD = 2v (cos c 4-Chamber, Mitral Regurgitation ) fT FLOW 2 High-resistance Arterial Flow Low-resistance 0 Doppler Principle BASELINE Respiratory/Cardiac Periodicity 2 Venous Flow Long Axis, Mitral Regurgitation Mitral Regurgitation Endocarditis (aortic valve) Aortic Stenosis Valvular/Subvalvular VSD (foal) Sublumbar Lymphadenopathy Invasive Retroperitoneal Mass