Congestive heart failure

Chronic management Posted by Ahmad Azizov on October 07, 2020

Congestive heart failure 

As we all know the blood flows from the left ventricle to the brain and the rest of the body. Then it is brought back by the venous system into the right atrium, right ventricle and the lungs. From the lungs, oxygenated blood travels into the left atrium and then the left ventricle to complete the cycle. In heart failure there is a problem with the heart, resulting in an ineffective cycle. 

Picture 1. The 2 great cycles of blood in the human body

Right heart failure 

Right sided heart failure is also known as diastolic heart failure and involves the failure of the right ventricle. As a result fluid backs up into the venous system. Acute right failure should be managed as hypertensive crisis

Left heart failure 

Left heart failure is also known as systolic heart failure and involves the weakening of the left ventricle. A weak left ventricle is not able to pump as efficiently and as a result, the blood is backed into the lungs initially. This eventually leads to a further back up into the right ventricle, right atrium and the venous system of the body. 

Presentation

Considering that the left-sided heart failure involves the weakening of the heart, leading to the congestion of the lungs it is easy to understand the symptoms of CHF. The classic presentation includes orthopnea, paroxysmal nocturnal dyspnea and dyspnea on exertion. The presence of all 3 is highly specific for having CHF while having none of them almost guarantees the absence of heart failure. Additionally CHF patients will also present with reduced forward flow leading to altered mental state (exacerbation state). Since the right and left ventricles are connected through the lungs, a backup within the lungs will certainly be transferred to the right side of the body resulting in the symptoms of right-sided heart failure. These include peripheral edema, abdominal pain (due to the edema in the bowel), elevated JVP and elevated LFTs

  • Lungs 
    • Pulmonary crackles
    • Kerley B lines on U/S
    • Pulmonary effusion 
  • Elevated JVP 
    • A sign of volume overload 
    • Associated with heart failure 
  • Edema 
    • Mostly peripheral 
    • Abdominal edema = abdominal pain 
      • Absorption of medicines and food is reduced
    • Weight gain 
  • Cardiac 
    • S3 on auscultation 
    • Displacement of the PMI 
  • Changed level of consciousness 
    • As a result of reduced forward flow into the brain 
      • Cardiogenic shock 
    • Signs of tiredness
  • Renal issues 
    • As a result of reduced forward flow into the kidneys 
      • Decreased GFR
    • Kidneys start to make renin 
    • Renin activates angiotensin ii
      • Increased aldosterone production 
        • Sodium resorption 
        • Water resorption 
        • Increased preload as a result of the above 2
      • Peripheral vasoconstriction 
        • Increased afterload 

Investigations 

  • BNP 
    • Best blood test for diagnosis 
    • <100 diagnosis excluded 
    • >500 highly likely for CHF 
    • Downfalls
      • Obese patients will have low BMP even in a CHF state - false negatives
      • Right heart strain due to chronic kidney disease, PE will elevate the BMP - false positives
    •  
  • Echocardiogram 
    • The best test to assess systolic vs diastolic heart failure
    • Will show the ejection fraction 
    • Should be repeated during an exacerbation 
    • If the ejection fraction is low 
      • Left-sided heart catheter to check for ischemia
  • ECG 
    • Can see old MIs and present arrhythmias 
  • Chest x-ray 
    • Can show fluid in the lungs and more

Diagnosis/Treatment 

The New York heart association class (NYHA) is the scale used to categorize patients with heart failure into functional categories. 

Table 1. The NYHA classes for CHF and the matching medications
Class  Description Treatment
I Completely asymptomatic. Can exercise at full capacity

Beta-blocker = Arrhythmia reduction

ACEi/ARB = Aldosterone reduction

II Can exercise. Dyspnea starts at full exertion. Daily tasks cause no dyspnea

Beta-blocker = Arrhythmia reduction

ACEi/ARB = Aldosterone reduction

Loop diuretics = Preload reduction

III Daily tasks cause dyspnea. No dyspnea at rest 

Beta-blocker = Arrhythmia reduction

ACEi/ARB = Aldosterone reduction

Loop diuretics = Preload reduction

Spironolactone/Bidil = Afterload reduction

IV Dyspnea at rest

Beta-blocker = Arrhythmia reduction

ACEi/ARB = Aldosterone reduction

Loop diuretics = Preload reduction

Spironolactone/Bidil = Afterload reduction

Milrinone/Dobutamine 

Left ventricular assist device (LVAD)

Heart transplant 

Additionally, patients with CHF with an ischemic etiology should also be placed on aspirin (ASA) and a statin. 

If the ejection fraction is below 35%, the patient will require a referral to an implantable cardioverter-defibrillator (AICD). This device is capable of performing cardioversion, defibrillation, and pacing of the heart, correcting most life-threatening arrhythmias.

Picture 2. An implantable cardioverter-defibrillator is used if EF is <35%

NYHA class 4 patients are very sick and do not receive AICD, and instead are considered for constant Milrinone/Dobutamine infusions, LVAD and a heart transplant. 

Picture 3. A left ventricular assist device is used temporarily before a heart transplant can take place

Lifestyle recommendations 

  • Sodium reduction 
    • < 2g salt daily 
    • < 2L water daily
  • Weight checks daily 
    • One of the earliest changes of heart failure exacerbation 
    • If weight increases >5 pounds in 48 hours, double the dose of the diuretic
  • Avoid NSAIDs
    • Can worsen the renal blood flow 

All information provided on this website is for educational purposes and does not constitute any medical advice. Please speak to you doctor before changing your diet, activity or medications. 


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Written by
Ahmad Azizov
Writing since 2020 April

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