N2161 - Week 10: HF/AFib

Afterload

Vascular resistance the heart must pump against.

Cardiac Output (CO)

The amount of blood pumped by the heart in one minute.

- Heart rate.

- Preload.

- Contractility.

- Afterload.

Four variables that CO is reliant on?

Cardiac Resynchronization Therapy (CRT)

Improves CO by synchronizing ventricles to beat together.

Internal Cardiac Defibrillator (ICD)

Prevents cardiac arrest from lethal arrhythmias.

Metered Dose Inhalers (MDI)

Produce local effects such as bronchodilation; some medications can lead to serious systemic side effects.

Preload

Amount of blood in the chamber at the end of diastole.

Heart Failure (HF)

Inability of the myocardium to pump sufficient blood to tissues.

HTN and CAD.

Most common causes of HF?

HF pathophysiology

Hypertrophic/Hypertrophy - Muscles become too thick, not leaving enough space in the ventricle for the blood (caused by HTN or genetics).

Dilated - Fluid build up over time causing dilation of heart and congestion (CHF).

chamber dilation cause

Fluid overload over time stretches out and dilates the chambers.

HF risk factors

- Myocardial ischemia (CAD/MI).

- Valve issues.

- Age.

- Dysrhythmias.

- Viral cardiomyopathy.

- HTN.

- Diabetes.

- CKD.

- Idiopathic.

- Alcohol and smoking.

- Systolic dysfunction (reduced ejection fraction).

- Diastolic dysfunction (preserved ejection fraction).

2 types of HF

Systolic Dysfunction

Inability of the LV to contract properly.

Diastolic Dysfunction

LV is unable to relax enough to allow normal diastolic filling.

- Pulmonary edema.

- Paroxysmal nocturnal dyspnea.

Manifestations of L sided HF?

Blood backs up into the lungs and causes pulmonary edema.

Reason for L sided HF manifestations?

Paroxysmal Nocturnal Dyspnea

Sudden SOB due to pulmonary congestion during sleep that is relieved with sitting up.

- Jugular vein distension.

- Peripheral edema.

- Ascites.

Manifestations of R sided HF?

Blood backs up into the systemic circuit.

Reason for R sided HF manifestations?

general HF SS

- Tachycardia.

- Arrhythmias.

- Edema.

- Fatigue.

- Palpitations.

- Dizziness.

- Low activity tolerance.

HF exacerbation precipitating factors

- Noncompliance with drug therapy.

- Increased metabolic demands.

- Fluid overload.

- Poor self-management.

- Uncontrolled HTN.

- Impaired contractility.

- Alcohol, smoking, and substance use.

HF diagnosis

- Echocardiogram.

- ECG.

- BNP.

- Cardiac MRI.

- MUGA scan.

- MIBI.

- Coronary angiogram.

- Chest X-ray.

Echocardiogram

Shows valves, measures size of chambers and ejection fraction.

ECG

Shows rate and rhythm, can also show LV hypertrophy.

BNP

Released in response to increased pressure within the heart.

Cardiac MRI

Can be used with contrast to determine viral/sarcoid/hemochromatosis.

MUGA Scan

Precisely measures EF.

MIBI

Stress test with contrast shows areas of ischemia.

Coronary Angiogram

Rules out ischemic causes of HF, can measure pressures within heart areas.

Chest X-Ray

Shows cardiac silhouette, cardiomegaly, pleural effusion, and pulmonary edema.

BNP.

Biochemical test of choice for diagnosing HF?

BNP normal range

<100-200 pg/mL.

INR normal range

INR normal range for warfarin

2.0-3.0.

Prothrombin Time (PT)

Measures in seconds how long it takes to form a blood clot.

PT normal range

10-13 seconds.

included in CP6

- Sodium.

- Potassium.

- Chloride.

- BUN.

- Creatine.

- Bicarbonate.

HF lifestyle changes

- Daily weights and report if gained >2 kg in 2 days.

- Medication adherence.

- Exercise 30-45 minutes 3x a week.

- Mediterranean diet, sodium and fluid restriction.

- Smoking cessation.

- Max 1 alcoholic drink per day.

- Vaccinations.

- Advanced care planning.

Atrial Fibrillation

Most common arrhythmia and is characterized by atrial tachyarrhythmia.

Paroxysmal AFib

Episodes of AFib that come and go.

Persistent AFib

More frequent episodes of AFib.

Permanent AFib

Constant state of AFib.

Blood pools in the atria and can form clots easily.

Why AFib is a risk factor for strokes?

AFib risk factors

- HTN.

- Age.

- Alcohol misuse.

- Valve issues.

- MI.

- Thyroid disease.

- Sleep apnea.

- HF and cardiac structural abnormalities.

- Stress.

- Genetics.

AFib pathophysiology

Multiple ectopic sites of impulse generation cause the atria to fibrillate.

Causes loss of atrial kick and 30% loss of CO.

How AFib decreases CO?

AFib SS

- Palpitations.

- Dizziness.

- Weakness.

- Anxiety.

- SOB.

Within 48 hours of symptom onset.

Timeframe that an individual can be cardioverted for AFib?