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