Session 10: Investigation and Management of Heart Failure Flashcards
Man comes in. 35 years old with profuse bilateral crepitations, loud murmur, breathlessness, sudden onset and fatigue. His O2 is at 91%. RR at 40. What is the treatment for the heart failure?
Intravenous furosemide 80mg Give oxygen Highly likely to require respiratory support Second line with i.v. nitrates and i.v. morphine
Explain mechanism of action of furosemide.
It as immediate venodilatory effect. It is a loop diuretic which inhibits the NA-K-Cl cotransporters in the thick ascending limb of the loop of Henle. It does so by binding to the chloride transport channel. This means that there is retention of sodium, potassium and chloride in the urine, so water will follow and reduce blood pressure.
Summary of the investigations done during suspected heart failure.
ECG Chest X-ray Bloods: FBC, NTpro-BNP and U&Es Transthoracic echocardiogram
Any further tests?
Maybe depending on clinical picture: Cardiac MRI scan to look for ischaemia Coronary angiography and or angioplasty Cardiomyopathy blood test screen e.g. haemachromatisus or Fabry’s disease.
Management for HFpEF.
Control BP and limited evidence of spironolactone working.
Management for valvular/strucular heart failure.
Surgery / keyhole surgery. You might have to put in a new valve or close a septal defect.
Management of right ventricular failure.
Since it is usually secondary to LV impairment, treat the LV impairment first.
Management of left ventricular systolic dysfunction.
Treat the underlying cause. If there is a chronic hypertension give something to lower the blood pressure. If it is arrhythmia - blood thinners and maybe a pacemaker Maybe biventricular defibrillator is needed In all of these cases furosemide may be used either IV due to acute heart failure or as oral if not acute.
Where would drugs be used to treat heart failure? (Where would they act)
They could act on the heart to reduced cardiac output. Can be used to inhibit the sympathetic nervous system Can be used to inhibit RAAS Can be used to increase fluid retention in urine.
Explain in more detail which drugs could be used in heart failure.
Digoxin to reduce inotropy and therefore reduce CO. Beta blockers to block the action on b1-receptors in the heart and also to inhibit release of renin. Renin inhibitors ACE inhibitors AT1 receptor antagonists (inhibiting angiotensin II from binding) Spironolactone which inhibits the actions of aldosterone by working as an antagonist. Diuretics which increases NA and water retention.
What is NTpro-BNP and why is it used in heart failure investigation?
How can the levels vary?
It is a hormone released in response to atrial/ventricular stretch due to fluid overload.
It has a high negative predictive value of 97% meaning if you don’t have an elevated level of NTpro-BNP you probably don’t have heart failure.
May vary with age and gender.
Atrial fibrillation can triple BNP/NTpro-BNP
