Cardiomyopathy Overview

Cardiomyopathy

• Group of diseases directly affecting the myocardial structure or function.
• Primary Cardiomyopathy is idiopathic.
• Secondary Cardiomyopathy stems from other diseases.

Types of Cardiomyopathy

• Dilated: Can result from drug and/or alcohol (EToH) use and coronary artery disease (CAD)
• Hypertrophic: Can result from hypertension (HTN).
• Restrictive: Can result from cancers.

Dilated Cardiomyopathy

• Most common type of cardiomyopathy.
• Causes heart failure (HF)
• A primary disorder with a genetic component.
• Alcohol use can cause dilated cardiomyopathy.
• Decreased contractility results in a decreased ejection fraction (EF) and cardiac output (CO).
• Compensation mechanisms include increased systemic vascular resistance (SVR) and preload, leading to dilated ventricles and heart failure with reduced ejection fraction (HFrEF).
• Characterized by diffuse inflammation and rapid degeneration of heart fibers.
• Leads to ventricular dilation, impaired systolic function, atrial enlargement, and blood stasis.
• Overstretched heart muscle loses its ability to recoil effectively.
• Causes cardiomegaly.
• Manifestations are similar to heart failure, but without hypertrophy or tissue enlargement.
• Symptoms may arise gradually or after a stressor.
• Other manifestations includes decreased exercise capacity, fatigue, decreased cardiac output, decreased pumping ability, and dyspnea at rest.
• Orthopnea (shortness of breath when lying down)
• Paroxysmal nocturnal dyspnea (episodes of severe shortness of breath and coughing that generally occur at night)
• Dry cough.
• Crackles.
• Jugular venous distention (JVD), hepatomegaly, and peripheral edema may occur.
• Palpitations occur due to septum stretch interfering with electrical impulses.
• Nausea/vomiting (N/V) and anorexia may occur.
• S3/S4 murmurs are present due to backflow issues.
• High risk of blood clots caused by blood stasis.
• Diagnostics include: Echocardiogram with low EF due to impaired systolic function.
• Chest X-ray (CXR) shows cardiomegaly.
• Electrocardiogram (ECG) shows tachycardic, bradycardia, dysrhythmia, and changes in electrical conduction.
• Elevated B-type natriuretic peptide (BNP)
• Possible heart catheterization may be needed to explore secondary causes or treatment options.
• The management is similar to heart failure protocols.
• Medications used are nitro, Lasix, beta-blockers, spironolactone, antidysrhythmics, and anticoagulation.
• Treat the underlying cause if secondary.
• Left Ventricular Assist Device (LVAD)
• Heart Transplant

Hypertrophic Cardiomyopathy

• Genetic disorder causing asymmetric left ventricular hypertrophy without ventricular dilation.
• Less common than dilated cardiomyopathy.
• More prevalent in males than females.
• Usually diagnosed in young adult athletes.
• Sudden death in young athletes is often related to undiagnosed hypertrophic cardiomyopathy.
• Impaired filling and left ventricular outflow tract obstruction (LVOTO) can occur.
• May present as heart failure with preserved ejection fraction (HFpEF) >40%.
• LVOTO involves an obstruction of blood flow from the left ventricle into the aorta due to mitral valve or other structural issues.
• Decreased systemic perfusion from low blood volume, increased heart rate, or increased contractility.
• Characterized by ventricular hypertrophy, rapid forceful contraction of the left ventricle, impaired diastole, and obstruction of aortic outflow.
• Causes poor cardiac output due to filling and outflow obstruction.
• Manifestations are due to decreased systemic perfusion/ischemia and may include:
• Asymptomatic presentation.
• Exertional dyspnea
• Fatigue.
• Chest pain is caused by the increased ventricular mass compressing the coronary artery.
• Syncope due to aortic outflow obstruction.
• Dysrhythmias like AFib, SVT, VT, VFib from high heart rate and high contractility.
• Diagnostics: -Echocardiogram -ECG showing ST and T wave abnormalities and presence of Q waves. -Dysrhythmias may be present.
• Cardiac catheterization is may or may not be performed.
• Management:
• Improve filling and relieve outflow obstruction
• Beta Blockers
• Calcium Channel Blockers
• Amiodarone
• Sotalol (closely monitored, initiated in hospital due to QT interval risks)
• AV Pacemakers
• Surgical intervention for hypertrophy
• Septal Myectomy
• Avoid Nitro

Restrictive Cardiomyopathy

• The least common type of cardiomyopathy
• Impaired diastolic filling and stretch with normal systolic function
• Cellular dysfunction prevents stretch
• Reduced filling leads to HFpEF (primarily right heart failure).
• Inability of the heart to pump adequate blood volume.
• Unknown cause
• Ventricles are resistant to filling, needing high diastolic filling pressures to maintain cardiac output.
• Secondary causes include:
• Amyloidosis: Accumulation of abnormal proteins (amyloid fibrils).
• Sarcoidosis: Granuloma formation.
• History of radiation to the chest.
• Manifestations:
• Fatigue
• Exercise intolerance
• Dyspnea
• Angina
• Syncope
• Palpitations
• Orthopnea
• Right-sided heart failure symptoms include an increase in preload.

Right-Sided Heart Failure Symptoms

• JVD (Jugular Venous Distention)
• Edema
• Ascites
• Hepatomegaly
• Changes to the ventricular wall.
• Diagnostics: -Echocardiogram -CXR showing cardiomegaly and pulmonary congestion -ECG shows AFib and AV block due to fibrosis.
• Management: -No specific treatment like heart failure treatment is done. -Avoid strenuous activity and dehydration.

Pacers and ICDs

• Passage of an electrical shock through the heart to depolarize myocardial cells and activate the sinoatrial (SA) node.
• Indications: -Ventricular fibrillation (VFib) -Pulseless ventricular tachycardia (VT) -Not used for asystole

Automatic External Defibrillator (AED)

• Detects heart rhythms.
• Identifies need for a shock.
• Delivers shock through hands-free pads.

Manual Defibrillators

• Interpret heart rhythm.
• Determine if shock is appropriate.
• Deliver the shock: 120-200 joules (biphasic) or 360 joules (monophasic).
• Turn off synchronizer during use.

Cardioversion

• Delivers a shock on the R wave of the QRS complex.
• Indications: -Ventricular tachycardia with pulse. -Supraventricular tachycardia (SVT). -Not for asystole or ventricular tachycardia without a pulse.
• Can be performed on a non-emergency basis.
• If the patient is awake, sedation is required to reduce pain.
• Low energy: 100 joules (monophasic) or 50-100 joules (biphasic) increase as needed.
• Monitor for loss of pulse, which can lead to ventricular fibrillation
• Turn on synchronizer when using Cardioversion

Implantable Cardioverter Defibrillators (ICD)

• Implanted subcutaneously over the pectoral muscle on the non-dominant side with a lead in the endocardium.
• Can sense VT or VFib.
• Delivers shocks at 25 joules.
• Can provide overdrive(anti-tachycardia) pacing of SVT, VT, or pacing for bradydysrhythmias.
• Alters repolarization to reset the SA node.
• Indications: -Prior sudden cardiac arrest -Spontaneous sustained VT -Syncope with inducible VT or VFib during EPS (extra pyramidal syndrome) -High risk for life-threatening arrhythmias. -MI, cardiac arrest, and cardiomyopathy.

Pacemakers

• Send electrical signals to the myocardium to stimulate contraction.
• Demand pacemakers sense adequate heart rate and inhibit electrical signal.
• Pace when necessary without QRS of intrinsic beat.
• May have overdrive pacing.
• Can pace in the atrium, ventricle, or both.

Types of Pacemakers

• Permanent: -Implanted.
  -for slow Heart rate from: Acquired AV block (2nd, 3rd degree), Atrial fibrillation with slow ventricular response, Idiopathic symptomatic bradycardia, and SA node dysfunction.
  -Helps heart pump more: Bundle Branch Block, Cardiomyopathy (Dilated, Hypertrophic, and HF), & Tachydysrhythmias.
• Cardiac Resynchronization Therapy: -Biventricle pacemaker -Paces both ventricles simultaneously, better synchrony -Can also have an ICD for heart failure with a history of dysrhythmia or arrest caused by loss of ventricle synchrony
• Temporary: -Transvenous: Leads inserted in ED or ICU to bridge for permanent pacemakers -Epicardial: leads attached directly during surgery for post-op dysrhythmias. -Transcutaneous: for emergencies

Complications for Pacers

• INFECTION
• PNEUMOTHORAX: lung puncture
• MALFUNCTION: Fire randomly, fibrosis, battery, electrical charge, and dislodgement.

Temporary/External Cardiac Pacing (Restrictions and Considerations)

• Avoid lifting the arm or shoulder on the side of placement.
• MRI is contraindicated.
• Travel is not restricted, but let TSA know and do not wand above the area.
• Avoid lingering near anti-theft devices.
• Delay driving.
• Avoid defibrillator pads over the device.
• Routine outpatient checks are required.
• Seek medical attention if the ICD fires.

Acute Coronary Syndromes (ACS)

• Chronic stable angina: has known triggers, activity, and relieved with rest and PRN medications like nitro

Unstable Angina

• Plaque rupture and thrombus formation partially occlude the coronary artery.
• Pain with Angina at rest or increases rapidly in short time
• Supply Ischemia NO INFARCT
• EKG finds Normal or T wave inversions or ST depression
• NEGATIVE troponin

NSTEMI (Non ST-Elevation Myocardial Infarction)

• Ruptured plaque and thrombus partially block affected coronary artery.
• Occurs in patient with history of heart diseases
• Results in myocardial cell death
• Results in a subendocardial myocardium
• EKG finds Normal or T wave inversions or ST depression
• POSITIVE troponin

STEMI (ST-Elevation Myocardial Infarction)

• EKG finds T wave or ST elevation.
• 100% artery occlusion and transmural damage
• Leads to transmural injury
• STEMI is MEDICAL EMERGENCY

ACS Management

• Cardiac cath reperfuse within 90 mins
• Thrombolysis use within 30 minutes if rural hospital

Other Manifestations

• Chest pain: Heavy, pressure, or crushing, usually with radiating pain
• Shortness of breath, Fatigue, or indigestion
• Patients may initially have high BP
• Patients may have a cool temperature
• May be found on 12 lead

ACS Medical Management Protocol within10min

• Nitroglycerin 1 Spray (0.4mg) sublingual PRN for chest pain, May repeat every 5min for max 3 sprays

• Morphine IV use for severe chest relieve cardiac workload

• Evaluate, anti plt, and anti-coag Therapy

• ANTI-PLT, use one of the folowing

• Ticagrelor 180 mg PO

• Clopidogrel 600 mg PO

• Prasugrel 60 mg PO

• Perform and physical exam

ACS Reperfusion Protocol

• Drive time must be
• Suggest, anticog, and Antiplt.
• ANTI-PLT: (one of the following) Ticagrelor 180 mg PO, Clopidogrel 600 mg PO, Prasugrel 60 mg PO
• ANTICOAG: Heperin or Heparin
• Recent (w/in past 3mon) ischemic stroke
• Severe, uncontrolled HTN
• Significant closed head or facial trauma w/in past 3 mon
• Antiplatelet meds: ASA, Plavix, brilinta
• Anticoagulants: Heparin, Lovenox, NITROGLYCERIN, ATORVASTATIN
• Reperfusion through stent in the cath lab.
• Complications of MI: Dysrhythmias:
• VT/VF
• Heart Block HF Reperfusion VT: rebound reperfusion VT so keep pads on

Other Complications

• Cardiogenic Shock
• Papillary Muscle Dysfunction or rupture: Septal wall to mitral valve so mitral function is limited
• Septal wall rupture a result to VSD

Pericarditis

• Inflammation. -Looks like a stemil on ECG

Dysrhythmias

• Disorders of Impulse Formation. All begin on : SA NODE, AV NODE, and BUNDLE BRANCHES & PURKINJE FIBRES
• Heart generates its own electrical impulses= AUTOMATICITY

Normal Interval Duration

• PR intervals: 0.12-0.2 sec
• QRS duration: <.12 sec
• QT interval: 0.34-0.43 sec
• • Each small block ECG strip is 0.2 seconds
• • 5 blocks group = 1 second

Tachycardia & Bradycardia H's & T's

• In 6 second strip use

• Causes

• HYPOVOLEMIA

• HYPOXIA

• HYDROGEN IONS (ACIDOSIS)

• HYPERKALEMIA/HYPOKALEMIA

• HYPOGLYCEMIA

• TOXIN/TABLETS

Tachycardia & Bradycardia Causes

• TAMPONADE
• THROMBOSIS: MI
• THROMBOEMBOLISM; PE
• TRAUMA

EKG Components: Normal Sinus

• 60 to 100 beats per minuit
• Normal P waves and follows QRS
• Qus is normal as well

EKG Components:Bradycardia

• Less than 60 beats per minuit
• Normal or normal athletic person
• Look at Eti

Atrial fibrillation

• Most common, manageable
• Prevalence increases w/ age, and Hx of heart disease, and other disease states -Increase risk of stroke

EKG: irregular pattern

• Tx, lower BMP
• Risk of AFIB RVR
• Tx: -Amiodarone
  • Digoxin

Premature Ventricular Contractions (PVCs)

• Wide and irrgegulars

• Treatment: Correct cause , Beta Blockers and Amiodarone