demystifying the cardiologist’s
TRANSCRIPT
Demystifying the Cardiologist’s Echocardiogram Interpretation and
How We Determine Further Imaging
Brandon Smith, MD
Objectives
• Review indications for echocardiography
• Discuss the process of transthoracic echocardiography
– Information gathered
– Limitations
• Review advanced imaging modalities and indications for use
Transthoracic Echocardiography
• Mainstay of pediatric/congenital cardiology
• Median 9,707 echocardiograms are performed at pediatric/congenital echocardiography labs per year1
1Srivastava et al Journal of the American Society of Echocardiography
Common Indications for Pediatric/Congenital Transthoracic Echocardiography
• Symptoms – Chest pain, palpitations, shortness of breath,
syncope, cyanosis
• Signs/Findings – Murmur*, cyanosis/failed CCHD screening,
abnormal pulses, abnormal ECG
• Associations – Chromosomal abnormalities, genetic syndromes,
family history
The Process
• Average time of 20 minutes to complete a full congenital transthoracic echocardiogram
• Requires a relatively cooperative patient – Movies for entertainment
– Patients 9-36 months can be challenging • Sedated echocardiograms are coordinated with Sedation Services
• Limitations – Air, lung disease
– Body type/habitus • Obesity, pectus
– Ports, tracheostomy, G-tube
Anatomic Relationships Normal
Anatomic Relationships Dextrocardia, Situs Inversus
Anatomic Relations Congenitally Corrected Transposition of the
Great Arteries
Anatomic Relationships
• Abdominal situs
• Cardiac position
• Atrial situs
• Atrio-ventricular connections
• Ventriculo-arterial connections
• Great artery relationships
Atrial Septum-Intact
Patent Foramen Ovale
Large Atrial Septal Defect
Atrial Septum
• Barriers to imaging include patient body habitus
• Abdominal gas
• Additional imaging by agitated saline (bubble study) can be performed; however, requires advanced planning
Systemic Veins-Normal
Systemic Veins-Left Superior Vena Cava
Pulmonary Veins
Tricuspid Valve
Tricuspid Valve
• Evaluate valve morphology
• Evaluate valve function
– Doppler for stenosis
– Trivial (physiologic) regurgitation is normal
– Tricuspid regurgitation is useful in estimating right ventricular pressure (pulmonary hypertension)
• <25 mmHg normal
Mitral Valve
Mitral Valve
• Evaluate valve morphology
• Evaluate valve function
– Doppler for stenosis
– Evaluate for prolapse
– Evaluate for regurgitation
Ventricles: Left and Right
Ventricles: Left and Right
• Size
• Wall thickness
• Systolic function
• Diastolic function
• Estimate right ventricular systolic pressure
– Evaluation of pulmonary hypertension
Ventricular septum
Aortic Valve
Aortic Valve
• Morphology
– Incidence of bicuspid aortic valve is approximately 1%2 with an estimated family incidence of 10-17%3
• Function
• Aortic root
2Ward, C. Heart 2000;83:81–85
3Beppu S, Suzuki S, Matsuda H et al. Rapidity of progression of aortic stenosis in patients with congenital bicuspid aortic valves. Amer J Cardiol 1993;71:322-327. Written by: S. LeRoy RN, MSN, Reviewed by D. Crowley, MD, April, 2003
Pulmonary Valve
Pulmonary Valve
• Function
– Trivial insufficiency is normal
• Useful for the evaluation of pulmonary hypertension
Coronary Arteries
Coronary Arteries
• Evaluate coronary artery origins
• Morphologic coronary abnormalities
• Coronary artery aneurysms/dilation
– Kawasaki
• Do not see distal coronary arteries routinely
– Do not evaluate for coronary artery disease
Aorta
Aorta
• Evaluate aortic root and ascending aorta dimensions
• Indirectly determine aortic arch sidedness
• Evaluate for coarctation
• Do not routinely evaluate head and neck vessels beyond the origin, abdominal aorta, or distal vessels
Pulmonary Arteries
• Pulmonary artery origins
• Pulmonary artery size
• Evaluate for branch pulmonary artery stenosis
– Trivial to mild peripheral pulmonary stenosis is common in infants
Systemic to Pulmonary Shunts
Systemic to Pulmonary Shunt
• Patent ductus arteriosus
• Small aortopulmonary collaterals and coronary to pulmonary artery fistulae are typically benign
Pericardium
Advanced Cardiac Imaging
• Transesophageal echocardiography
• Cross-sectional imaging
– Cardiac CT
– Cardiac MRI
Transesophageal Echocardiography
Transesophageal Echocardiography
• Allows for imaging of intra-cardiac structures without limitations of lung artifact
• Requires sedation/anesthesia
• Indications – Poor transthoracic windows
– More detailed evaluation of cardiac structures • Valves (endocarditis); atrial septum
– Peri-procedure • pre- and post-operative, atrial and ventricular septal defect
device closure
Transesophageal Echocardiography
Cross-sectional Imaging
• Allows for complete 3D anatomical assessment (cardiac CT and MRI)
• Obtain ventricular volumes and systolic function (cardiac MRI is the gold standard)
• Assess valvar regurgitation and vascular flow (cardiac MRI)
• Evaluate extravascular structures (cardiac MRI and CT)
Cross-sectional Imaging Comparison
Cardiac CT Cardiac MRI • Advantages of Cardiac CT
– Complete 3D anatomic assessment – Rapid acquisition time
• Sedation/anesthesia is often not needed
– Less susceptibility artifact from metallic interference
– High spatial resolution
• Disadvantages – Ionizing radiation (0.2-0.3 mSv) – Iodinated contrast – Vessel flow – Valvar regurgitation in >1 lesion – Myocardial tissue characterization
• Advantages of Cardiac MRI – Complete 3D anatomic assessment – 4D (flow) assessment – Gold standard for ventricular volume and
systolic functional assessment – Gold standard for valvar regurgitation – Gold standard for myocardial tissue
characterization – No ionizing radiation
• Disadvantages of Cardiac MRI – Acquisition time (30-60 minutes)
• Sedation/anesthesia in patients < 8 years
– Susceptibility artifact metallic interference • Sternal wires, stents, coils, valves • Pacemakers, ICDs
Native Coarctation
Summary
• Transthoracic echocardiography is the primary imaging modality of pediatric/congenital cardiology
• Provides a detailed assessment of cardiac anatomy and function
• Evaluation can be limited by patient habitus, imaging windows, and degree of cooperation
• Advanced imaging modalities available
• Heart Center is available for questions