Managing Hypertrophic Cardiomyopathy with Imaging Gisela C. Mueller University of Michigan Department of Radiology
Disclosures Gadolinium contrast material for cardiac MRI
Acronyms Afib CAD Atrial fibrillation Coronary Artery Disease PVC RF Premature ventricular contraction Radiofrequency HCM Hypertrophic Cardiomyopathy SAM Systolic anterior motion of mitral valve LA Left atrium SAX Short axis view LV Left ventricle SCD Sudden cardiac death LVOT Left ventricular outflow tract Vfib Ventricular fibrillation NSVT Non-sustained ventricular tachycardia Vtach Ventricular tachycardia
Agenda I. HCM: Management and Diagnostic Issues II. III. IV. Prevention of SCD CMR: Late Gadolinium Enhancement Dynamic LVOT and Mid-cavity Obstruction V. Heart Failure and Atrial Fibrillation VI. VII. Early Markers of HCM Differential Diagnoses VIII. References
I. Management and Diagnostic Issues
Br Heart J 1958 20: 1-8 Autosomal dominant LV Hypertrophy: unexplained = Absence of disease that would be capable of producing the magnitude of hypertrophy evident in a given patient Non dilated ventricular chamber
Prognosis Most common: normal life expectancy, and no major complications
Complication Prevention or Intervention Vtach/Vfib => SCD (most common 35 years of age) ICD for SCD prevention Heart failure (diastolic and/or systolic) Atrial fibrillation (associated with stroke) Heart failure drugs surgical myomectomy or alcohol septal ablation if heart failure 2 nd to LVOT obstruction Heart transplant Anticoagulation, heart rate/rhythm control RF ablation Surgical maze procedure Gersh et al: Circulation. 2011;124:e783-831
Management Issues Counseling (lifestyle, genetic testing) SCD Risk Assessment and Prevention Diagnosis and treatment of dynamic LVOT and cavity obstruction Prevention, diagnosis, and treatment of heart Failure and atrial fibrillation Family counseling and screening of family members of HCM patients Monitoring of gene carriers for development of the HCM phenotype
HCM Management: Role of Imaging SCD Risk Stratification Diagnosis and monitoring of heart failure Evaluation of dynamic LVOT and cavity obstruction Pulmonary Vein Imaging for treatment of Afib Family Screening Monitoring of Gene Carriers for Development of Hypertrophy CMR, Echo Echo, CMR Echo, CMR CT, CMR Echo, CMR Echo, CMR
Diagnostic Issues Other Conditions with LV Hypertrophy Athlete s Heart Diagnostic Methods EKG, Echo, CMR, deconditioning Systemic Hypertension Blood pressure monitoring and treatment, EKG, Echo, CMR Aortic Valve Stenosis Amyloid Echo, CMR, CT, EKG, Echo, CMR, pathology Glycogen Storage Disease EKG, Echo, CMR, pathology Noncompaction Echo, CMR
II. Prevention of SCD
Secondary prevention: after the patient had an arrest Primary prevention: before the patient had an arrest
Personal History: Vfib; sustained Vtach; aborted SCD Yes ICD recommended No Risk Stratification for primary SCD prevention ICD reasonable indeterminate ICD not reasonable Assess potential risk modifiers
Risk Stratification for Primary Prevention of SCD ICD is reasonable if one of the following applies: maximal myocardial thickness 3 cm Family history of HCM related SCD in one or more firstdegree relative Personal history of one or more recent unexplained syncopal episodes ICD can be useful, particularly if other risk factors or risk modifiers present, if NSVT = Ventricular tachycardia (3 or more beats at 120 bpm) with a duration of less than 30 seconds) Systolic blood pressure rises < 20 mm Hg or decreases during exercise Gersh et al: Circulation. 2011;124:e783-831
Maximal Myocardial Thickness ECHO Limited visualization: large patients, apex, anterior wall Most common site of maximal thickness: anterior septum parasternal long axis view Sometimes difficult delineation of RV border of septum CMR Entire myocardium visualized Most common sites of maximal thickness: intersection of anterior septum and anterior wall; inferior septum Short axis view Good delineation of RV border of septum
Potential SCD Risk Modifiers Are considered if conventional risk stratification is indeterminate Delayed enhancement of myocardium on CMR Marked LVOT obstruction Double and compound mutations
CMR: Late Gadolinium Enhancement
Delayed Enhancement > 50% of patients with HCM Thought to represent replacement fibrosis Caveat: sparse pathologic data, limited to end-stage disease) More common in hypertrophied areas of myocardium and related to extent of hypertrophy Inversely related to LVEF Associated with NSVT and PVCs (Holter monitoring)
FWHM (dual threshold): Core tissue: 1.10g ( 1%) Grayzone: 74.62g (41%) 6 SD/ 4SD (dual threshold) Core tissue: 39.47g (21%) Grayzone: 21.12g (11%)