Cardiomyopathies 2025 - Part 2 PDF

1/16/2025 Dilated Cardiomyopathy Heart Transplant Biatrial anastomosis transplantation Hea...

1/16/2025 Dilated Cardiomyopathy Heart Transplant Biatrial anastomosis transplantation Heart transplant Associated with arrhythmias, TV dysfunction, thrombus formation Evaluate for rejection and atrial dysfunction Double “P” wave seen on ECG 2D Bicaval anastomosis transplant Doppler Entire RA removed Preserves atrial contractility, sinus node function, tricuspid valve competence Longer procedure 41 42 Heart Transplant Heart Transplant Transplant rejection evaluation Echo findings of rejection Rejection risk highest in first 3 months post transplant Earliest finding is PE and increased wall thickness Endomyocardial biopsy is gold standard presumably due to inflammation and myocardial First year anywhere from 8-12 biopsies performed edema Not always present One-year post-transplant Decreased LVF (more with end stage rejection) Annual coronary angiogram Acute MI Dobutamine stress echocardiography Transplant patients have an accelerated rate of Intravascular coronary ultrasound coronary atherosclerosis Echocardiograms ≈ every 6 months Doppler Blood work every 2-3 months Diastolic function usually abnormal TDI parameters show hope but currently there is no combination that is considered a reliable indicator 43 44 Noncompaction Unclassified cardiomyopathy Ventricular Noncompaction Disease of endomyocardial trabeculations Myocardial structure altered Consists of two layers: Thin, compacted myocardium on the epicardial side Thicker noncompacted endocardial layer Borges, A C et al. Heart 2003;89:21e Copyright ©2003 BMJ Publishing Group Ltd. 45 46 1  1/16/2025 Noncompaction Noncompaction Thought to be caused by arrest of normal Echo criteria embryogenesis Determine the absence/presence “Compaction” occurs between wks 5 - 8 of coexisting cardiac abnormalities Proceeds from epicardium to endocardium, and base E.g., semilunar valve obstruction, to apex coronary artery anomalies Coronary circulation develops at the same time Two-layer structure Predominantly localized to mid-lateral, Compacted thin epicardial band apical, and mid-inferior areas Thick noncompacted endocardial Mid-anterior wall, septum and basal segments layer of trabecular meshwork with deep endomyocardial spaces involved less frequently End-systolic ratio of NC/C layers >2 47 48 Noncompaction Noncompaction LV most affected Predominant localization to mid-lateral, apical, and mid-inferior areas Mid-anterior wall, septum and basal segments involved less frequently May involve both ventricles (22-38% of patients) 49 50 Noncompaction Noncompaction Color Doppler and/or contrast echo can help with diagnosis Manifests in heart failure (most common), arrhythmias, Management embolic events Treatment for CHF Antiarhythmic therapy ICD Bi-V pacer Long term anticoagulation Screening first degree relatives 51 52 2  1/16/2025 Hypertrophic Cardiomyopathy Heart muscle becomes hypertrophied in the absence of increased afterload Hypertrophic Cardiomyopathy If the wall thickness is great enough, or occurs in a specific location, it can lead to obstruction of outflow HCM is either obstructive or nonobstructive 53 54 Hypertrophic Cardiomyopathy Hypertrophic Cardiomyopathy Histologically the muscle tissue appears different from normal Normal myocardial myofibrils neatly arranged Family members of patients with HCM Hypertrophic myofibrils in chaotic disarray should undergo echo screening to help Abnormally short, broad, hypertrophied Can run in different directions, with complex intercellular bridging with early diagnosis and management resulting in formation of whorls Believed to be autosomal dominant genetic trait History of recurrent syncope and family history of sudden cardiac death Individuals with unexplained syncope 55 56 Hypertrophic Cardiomyopathy Hypertrophic Cardiomyopathy Younger individuals are likely to have a more severe form of HCM HCM can appear as concentric HCM is the most common cause of sudden cardiac hypertrophy death in young persons - young athletes in Sometimes difficult to differentiate from particular physiologic hypertrophy LVH due to HTN, AS, other disease processes Most sudden deaths thought to be due to Patient history may help you determine whether complex ventricular tachyarrhythmias the patient has a reason to have LVH, but the cause generated by electrically unstable myocardium is not always clear Ventricular fibrillation most common Concentric hypertrophy is an important finding with HCM but it is not very specific 57 58 3  1/16/2025 Hypertrophic Cardiomyopathy Hypertrophic Cardiomyopathy Asymmetric Septal Hypertrophy (ASH) Hypertrophy in HCM is often Septum to posterior wall ratio of 1.3: 1 asymmetrical Seen on m-mode or 2D Asymmetric Septal Hypertrophy (ASH) Septum is thicker than the other walls Can also extend to the anterolateral wall Careful, other states such as PHTN with RVH and inferior wall infarction in the presence of concentric hypertrophy can result in similar appearance 59 60 Hypertrophic Cardiomyopathy Hypertrophic Cardiomyopathy M-mode of ASH Obstructive myopathy Known as: HOCM Hypertrophic Obstructive Cardiomyopathy IHSS (classic HOCM) Idiopathic Hypertrophic Subaortic Stenosis Characterized by a dynamic outflow obstruction Involves either the MV apparatus or LV muscle tissue itself 61 62 Hypertrophic Cardiomyopathy Hypertrophic Cardiomyopathy Mitral outflow obstructions caused by systolic Causes of SAM anterior motion (SAM) of the mitral leaflet or chords Abnormal relationship of papillary muscles and MV or apparatus moves towards the IVS and obstructs chords combined with hyperdynamic LV ejection outflow M-mode or 2D to document SAM Results in varying portions of the MV apparatus in being displaced in systole Venturi effect High velocity flow moving against the septum, slowing the red blood cells along the edge more than those on the outside of the flow pattern Causes low pressure zone that pulls the MV and MV apparatus anteriorly and into the outflow tract, causing obstruction 63 64 4  1/16/2025 Hypertrophic Cardiomyopathy Hypertrophic Cardiomyopathy Degree of obstruction depends on amount Chordal or MV SAM interrupts outflow of of contact of the MV with the septum and blood flow the duration of contact AV notch n M-mode (pre-closure of AV) Usually, obstruction occurs when SAM persists Due to sudden decrease in flow secondary to outflow obstruction the AV starts to close (mid systolic for 40% of cardiac cycle notching) 65 66 Hypertrophic Cardiomyopathy Hypertrophic Cardiomyopathy Doppler documents and quantitates obstruction CW evaluates peak gradient in outflow region Why do Doppler signals peak late in Late peaking gradient obstructive patients? Dagger shaped profile (typical concave profile) Because in early systole there is more volume in Distinct from AS or MR the LV keeping obstructive components as far from each other as possible. As systole progresses the cavity gets smaller, worsening obstructive process as components move closer Maximal gradient occurs in late-systole, after majority of LV ejection occurred Not obstructive in respect to flow volume since most was ejected at the time the obstruction develops 67 68 Hypertrophic Cardiomyopathy Hypertrophic Cardiomyopathy About 25% of patients have HOCM – defined as an LVOT gradient of at least 30mmHg Should try to provoke an obstruction Maneuvers that increase contractility, reduce LV volume or decrease resistance to LV outflow may unmask a hidden gradient Valsalva Amyl nitrate inhalation Changes in body position (sitting/standing) Velocities increase across an obstruction that already existed at rest 69 70 5  1/16/2025 Hypertrophic Cardiomyopathy Hypertrophic Cardiomyopathy Valsalva maneuver Careful – Do not Valsalva patients that already Bearing down on the abdominal muscles while at have a very high gradient at rest the same time trying to exhale against a closed Valsalva may cause the patient to become light- airway momentarily stops venous return headed or pass out On relaxation a rush of blood fills the heart, causing an increased SV and force of contraction Gradients (Frank-Starling Principle) Fixed An obstructive gradients will be demonstrated Valsalva maneuver has no effect on the gradients easily by the increase in velocity Dynamic Gradient has variance and can be made worse with maneuvers 71 72 Hypertrophic Cardiomyopathy Hypertrophic Cardiomyopathy PW used to track ejection velocities and identify location of obstruction Starting at AV and work towards apex Dynamic obstruction causes Point of highest velocity is the point of greatest obstruction marked turbulence seen with color Doppler MR common finding of HOCM Malcoaptation of leaflets due AV level to tethering with SAM Jet usually posteriorly directed Usually mid to late systolic than holosystolic During maximal SAM Hyperdynamic pressure in LV increases in mid to late systole 73 74 Hypertrophic Cardiomyopathy Hypertrophic Cardiomyopathy MR severity varies HOCM can occur with or without MV SAM Related to the degree of anterior Obstructive without SAM leaflet SAM and the length and Small LV cavity size mobility of the posterior leaflet Small LV end systolic volume More severe can contribute to Dynamic LV contraction symptoms Thickened LV walls Prominent papillary muscles Make sure not to confuse MR with Obstruction often occurs mid ventricle LVOT gradient No MV SAM during systole MR often earlier onset than LVOT Obstructive with MV SAM profile and velocities are LV cavity size - normal or mildly decreased supraphysiologic MV SAM during systole 75 76 6  1/16/2025 Hypertrophic Cardiomyopathy Hypertrophic Cardiomyopathy Nonobstructive signs Signs of HOCM Thickened LV walls Thickened LV walls No increased afterload to account for the Asymmetric thickening of the IVS LVH Technically, cardiomyopathies are only disorders Notching and pre-closure of the AV that cannot be explained by a primary cause Increased velocities across the septum and E.g., Patient with LVH and HTN - not a LVOT cardiomyopathy LVH with hyperdynamic function SAM of the MV Physical proximity of the LV walls during systole leads to obstruction of flow All the above are signs of classic IHSS 77 78 Hypertrophic Cardiomyopathy Hypertrophic Cardiomyopathy HCM impairs diastolic relaxation Can result in symptoms of heart failure despite normal and often increased EF due to high filling pressures, which result in pulmonary congestion 79 80 Hypertrophic Cardiomyopathy Hypertrophic Cardiomyopathy Variants Apical hypertrophy Normal thickness at base Markedly diminished apical cavity w/ spade-shaped cavity Careful – can be missed with low frequency transducer Use higher frequency, shallow focal depths, color Doppler (with lower Nyquist limit), contrast echo Mid ventricular obstruction Possibly due to long standing HTN and small LV cavity Color flow or contrast may demonstrate obstruction Hypovolemia Can result in small chamber and dynamic contraction Acquired form of outflow obstruction Apical hypertrophy 81 82 7  1/16/2025 Hypertrophic Cardiomyopathy Hypertrophic Cardiomyopathy Distinguishing obstructive from nonobstructive Medical therapy – beta blockers or calcium channel forms of HCM, based on the presence or blockers have proved limited benefit absence of an LV outflow gradient, may be Decrease the force of contraction and discontinuance of critical for choosing management strategies nitrates and diuretics Even though a gradient may be evident when Invasive treatments reserved for patients with severe symptoms despite medical treatment the patient is at rest, in many cases it is latent Usually, LVOT gradients of > 50 mm/hg and can be identified only with exercise or a Approximately 5% of HCM patients are candidates for Valsalva type maneuver invasive treatment 83 84 Hypertrophic Cardiomyopathy Hypertrophic Cardiomyopathy Pacemakers Ventricular septal myotomy- Not a primary treatment for HCM, but may be myectomy considered in selected patients (e.g., elderly Surgical resection of patients who are poor surgical candidates) hypertrophied IVS Basic pacemaker Small amount of the thickened A carefully placed pacemaker lead can cause abnormal septal septal wall is removed to widen the motion, and in theory increase the available outflow area, outflow tract reducing the gradient Eliminates obstruction and MR Dual-chamber pacing (Bi-V pacing, CRT) Rapid relief of symptoms Proposed method for decreasing symptoms and improving the Complications: LBBB, VSD, hemodynamics in the outflow obstruction Clinical trials show little evidence of improved exercise atrioventricular conduction block, capacity arrhythmias, and AI 85 86 Hypertrophic Cardiomyopathy Hypertrophic Cardiomyopathy Alcohol septal ablation Gaining popularity - easier to perform then myectomy Small amount of absolute alcohol is injected into the septal branch of the LAD artery supplying the hypertrophied portion of the IVS Causes controlled MI Reduces obstruction and improves symptoms Reduces severity of MR 87 88 8  1/16/2025 Hypertrophic Cardiomyopathy Hypertrophic Cardiomyopathy Alcohol Septal Ablation Possible long-term risk MVR for arrhythmias from Removal of the MV myocardial scarring from and placement of a ablation, and superior exercise testing results mechanical one to with surgery, septal eliminate myectomy remains gold standard for severely obstructive SAM symptomatic HCM patients w/ marked LVOT obstruction that does not respond to maximal medical management 89 90 Hypertrophy Hypertrophy Types Symmetric hypertrophy vs. Asymmetric hypertrophy 91 9