• • Hemochromatosis (labs show elevated Fe and liver enzymes) ➔ restrictive or dilated

  • MYH7 mutations ➔ altered β-heavy chain

  • TTN gene mutations ➔ altered titin protein which is involved with sarcomere springing back

• Virus goes right into cardiomyocytes ➔ cytotoxicity or virus causes autoimmune response

  • Lyme usually causes conduction issue (AV block)

• Sarcoidosis causes a reversible DCM

• Cardiac myocyte issue (from infection/toxin) or tachyarrhythmia ➔ ↓ contractility ➔ compensation to keep up cardiac output ➔ ↑ preload

• Blood going back into ventricle (mitral/aortic regurgitation) ➔ ↑ preload

↑ end-diastolic volume/EDP (PRELOAD)

• ↑ preload ➔ eccentric remodeling (sarcomeres are added in series to existing sarcomeres)

• ➔ ↓ myocardial contractility ➔ ↓ ejection fraction (systolic problem)

  • For funzies:

    • Chronic HTN or aortic valve stenosis ➔ concentric hypertrophy (stiff) (new sarcomeres added in-parallel to existing sarcomeres)

    • ↑ Wall thickness ➔ impaired filling ➔ diastolic dysfunction

• S3 occurs during rapid-passive filling at the start of diastole.

  • Once enough blood pools in atria the trap door (valve) opens and dumps the blood into a dilated ventricle

    • I think of it like an echo in a canyon

  • Athletes have a "healthier" eccentric remodeling and pregnant pts have a little bit more volume (S3 maybe normal finding in these pts)

  • S4 - "lalub-dub" happens with active filling (when the atria give that last little squeeze) late in diastole

• Big left ventricle moves (displaces) maximal impulse from 5th intercostal at mid clavicular line toward axillary line

  • Diameter: discrete/≤ 2 cm ➔ > 3 cm (signals left ventricular enlargement)

  • Amplitude: brisk and tapping ➔ diffuse low-amplitude (hypokinetic)

  • Duration: ≤ 2/3 of systole ➔ sustained

Little bit of a HF reminder:

• Systolic dysfunction (stretched heart) ➔ forward failure

  • ↓ output ➔ shocky (hypotension, cold peripheral)

• Backed up left side means the pulmonary circulation is backed up ➔ backward failure

  • ↑ pulmonary vein pressure ➔ pulmonary congestion ➔ fluid forced into interstitium (extravasated)

• Echo shows function (ejection fraction) and extent of remodeling

  • Doesn't help with etiology so if it seems idiopathic and you're asked to find the cause... you might want to answer something about genetics.

• Acute HF: Sit them up, diuresis if pressure > 90mmHg, positive pressure ventilation (BVM/CPAP/intubate)

• Anticoagulation for a-fib/valvular issues

• Don't pick digoxin unless all of the other choices are definitely wrong

• Heart transplant if all else fails

• Click here for more on acute CHF