Cardiomyopathy: Types, Causes, and Manifestations

Cardiomyopathy Overview

• Diseases impacting myocardial structure/function
• Can be either primary (idiopathic) or secondary to other conditions like drugs, alcohol, CAD, hypertension, or cancer

Dilated Cardiomyopathy

• The most common type of Cardiomyopathy
• Often linked to heart failure (HF), and is sometimes genetic
• Causes include alcohol use
• With decreased contractility, ejection fraction (EF) and cardiac output (CO) decrease which triggers compensation such as increased systemic vascular resistance (SVR) and preload
• Compensation leads to dilated ventricles
• Leads to Heart Failure with reduced Ejection Fraction (HFrEF)
• Characterized by inflammation and rapid degeneration of heart fibers, as well as ventricular dilation, atrial enlargement, impaired pump function, and blood stasis
• Has been likened to an overstretched rubber band losing recoil
• Results in cardiomegaly
• Manifestations are similar to HF, but without hypertrophy or tissue enlargement
• Symptoms develop gradually or after a stressor like decreased exercise capacity, fatigue, decreased CO, dyspnea, orthopnea, and paroxysmal nocturnal dyspnea, dry cough, crackles, JVD, hepatomegaly, peripheral edema, palpitations, nausea, anorexia, S3/S4 murmurs, and high risk for blood clots

Dilated Treatment and Diagnosis

• Diagnosed using ECHO (low EF), CXR (cardiomegaly), ECG(arrhythmias), elevated BNP, and cardiac catheterization
• Management similar to HF such as Nitro, Lasix, beta-blockers, spironolactone, antidysrhythmics, anticoagulation, LVAD, and possibly heart transplant

Hypertrophic Cardiomyopathy

• Genetic disorder causing asymmetric left ventricular hypertrophy without dilation
• Less frequent than dilated cardiomyopathy
• More common in males
• Often diagnosed in young athletes

Hypertrophic: Impaired Filling and LVOTO

• Related to undiagnosed cases
• Can be heart failure with preserved ejection fraction (HFpEF >40%)
• Left Ventricular Outflow Tract Obstruction (LVOTO) obstructs blood flow from the left ventricle to the aorta due to mitral valve or structural blockages
• Systemic perfusion is decreased
• May result in low blood volume, increased heart rate, or increased contractility

Hypertrophic: Characteristics and Diagnosis

• Has ventricular hypertrophy, forceful contraction, impaired diastole, and aortic outflow obstruction
• Causes poor cardiac output due to filling and outflow issues
• Some individuals have mild to no symptoms
• Symptoms: exertional dyspnea, fatigue, chest pain (increased ventricular mass compresses the Coronary Artery.), syncope (aortic outflow obstruction), and dysrhythmias
• Diagnostic: ECHO, ECG (ST and T wave abnormalities, Q waves)

Hypertrophic: Treatment

• Some may need a heart catheter
• Improve filling and reduce obstruction through beta- and calcium channel blockers like amiodarone, sotalol, AV pacers, surgical intervention
• Nitroglycerin is contraindicated

Restrictive Cardiomyopathy

• The least common type
• Features impaired diastolic filling/stretch, systolic function is fine
• Cellular dysfunction prevents stretching, leading to reduced filling
• Considered HFpEF
• Unknown cause and secondary etiologies
• Ventricles resist filling, needing high diastolic pressures to maintain CO
• Secondary causes include amyloidosis (abnormal protein build-up) and sarcoidosis (granuloma formation) as well as history of radiation

Restrictive: Manifestations, Diagnosis, and Treatment

• Causes fatigue, exercise intolerance, dyspnea, angina, syncope, palpitations, orthopnea, right-sided HF, JVD, edema, ascites, and hepatomegaly, and changes to the ventricular wall
• Diagnosable with ECHO, CXR (cardiomegaly and pulmonary congestion), and ECG (AFIB, AV block)
• Non-specific treatment: Similar to HF management with avoided dehydration

Defibrillation Overview

• Delivers electrical shocks to depolarize heart cells to help with pacing
• Delivers electrical shock to depolarize myocardial cells, to activate SA Node
• Used for VFib, Pulseless VT

AEDs and Manual Defibrillators

• AUTOMATIC EXTERNAL DEFIBRILLATOR (AED) can detect rhythms for arrhythmias
• Delivers shock if indicated with hands-free pads
• MANUAL DEFIBRILLATORS are able to Interpr heart rhythms and Deliver shock if appropriate
• You deliver the shock: 120-200 joules if biphasic and 360 is monophasic
• Turn the synchronizer off

Cardioversion

• Delivers a shock on the R Wave of the QRS
• Used for VT with pulse, and SVT, though it is not for asystole and VT without a pulse
• Can be nonemergency
• The patient needs sedation
• Low energy: 100 joules for monophasic, 50-100 biphasic, increase as needed
• Patient can lose the pulse leading to VFIB
• Turn the synchronizer on

Implantable Cardioverter Defibrillators (ICDs)

• Implanted subQ over pectoral muscle with lead in the endocardium on the non-dominant side
• Senses VT/Vfib
• Delivers shocks at 25 joules
• Provides overdrive pacing (anti-tachycardia) of SVT/VT or pacing for bradydysrhythmias
• Paces at a higher rate than the current rate to change the pattern of repolarization to reset SA node
• Used for prior sudden cardiac arrest, spontaneous VT, syncope with inducible VT/VFib, life-threatening arrhythmias, MI, cardiac arrest, or cardiomyopathy

Pacemakers

• Types: Permanent and Temporary
• Sends electrical signals to the heart muscle
• Demand Pacemakers sense the heart rate
• Temporary situations are Epicardia, Trans Venous and Trans Cutaneous

Permanent Pacemakers

• Implanted in the body
• Used for slow HR due to acquired AV block, afib , bradycardia, or SA node dysfunction while helping with efficiency and bundle branch block, cardiomyopathy or heart rates related to HTN
• Types: Cardiac Resynchronization Therapy

Cardiac Resynchronization Therapy

• Biventricle pacemaker
• Paces both ventricles, giving the ventricles synchrony
• They can also have an ICD
• It is Hf caused by a dysrhythmia
• Indications is to restore ventricle synchrony

Temporary Pacemakers

• Transvenous use leads for bradydysrhythmias
• Epicardia can be used to attach since the leads are located there
• Transcutaneous use pacing pads; is emergent; and needs conscious sedation
• Indications of reduced CO affecting heart rate

Complications with Pacers and ICDs

• Infection
• Pneumothorax
• Requires a CXR after placement
• Malfunctions- Failure to Sense or Capture, and Over/Under Sensing

ICD and Pacemaker Restrictions

• Avoid excess use of the part of the body where it was placed
• Avoid MRIs
• Notify security during travels or avoid theft devices in stores; also delay driving
• These need to be checked regularly
• Patients need to be screened following a firing

Acute Coronary Syndromes (S/Sx)

• Unstable Angina
• NSTEMI
• STEMI

Unstable Angina

• PLaque rupture and thrombus will form; causing artery occulsion
• Causes angina pain
• Does not cause infarction
• T/ST are normal
• Troponin is -
• S/Sx will cause pain; occur at rest; last for 10mins

NSTEMI

• Plaque rupture with thrombus; causes partial occlusion of arteries; d/t HX
• Occurs in myocardium cells; subendocardial
• Normal to inverted T/ST and + Troponin
• Managed with medicine and does not need fixing ASAP

STEMI

• Total occlusion; causing injury and infarction
• Troponin Positive
• S/SX will cause pain

Testing and Interventions

• T waves or ST Elevation
• Medical Emergency; must be done ASAP
• Door to reprofusion- 90mins
• Needs to be performed within 120mins

Manifestation of STEMI

• Heavy; pressure, tight chest pain
• Radiating pain
• SOB; fatigue, indigestion
• HR and BP are increased with cool skin
• Manifestations : HF
• Fecer response

Diagnostics for STEMI

• EKG -12 Lead : ST and T waves
• ECG : At least 2mm or 1mm and not LEFT rhythm

Suspected MI Protocol Medications

• Troponin +
• Obtain EKG in 10 mins
• Defib pads; get VS
• Administer chews ASA 162

Medication - Chest Pain

• Nitroglycerin for pain
• Morphine for pain unrelieved
• Reperfusion as needed
• Antiplt or Coagulations : (One of the Following)
• Ticagrelor and Clopidogel for anticoagulation

Other Medications needed for Susopected MI

• HEP for anticoagulation
• TPa

Contraindications for Using TPa Medications

• Active Bleeding
• Brain Issues
• Cancers
• Witin 3months
• BP issues or facial scaring

Meds for managing suspected MI

• Suspected Aortic Dissection
• Mona
• STEMI meds

Med Management (Complications)

• ASO antiplt
• Heparin for anticoagulation
• Nitro for Low BP
• 02 as needed
• beta blockers

Complications of MY

• Can cause dyshythmia (VT or HF)
• Cardio shock or rupture
• Pericarditis which requires more care

Recovery of MI complications

• Development if more Pericarditis
• Patients and Immune systems attacks
• Need to promote recovery to decrease stress
• Provide medications; promote wellness

Dysrhythmias

• Electrical impulses can cause this
• Automaticity is important
• Check PR and QRS
• Each block counts 0.2seconds