HEART DISEASE

The management of heart disease must be based on an understanding of the unserlying conditions, particularly ischaemic heart disease, cardiac failure and atrial fibrillation. There have been important advances in the diagnosis and management of these conditions that have altered our approach to patients:

1. Active management of myocardial infarction:

-the use of troponin-T and other markers for risk stratification.

-urgent re-perfusion by medical intervention and/or balloon angioplasty in acute myocardial infarction.

-aspirin prophylaxis.

-beta-blockers and intensive lipid-lowering therapy with statins to improve long-term outlook.

-referral of unstable patients for CABG (coronary  artery bypass grafting) or angioplasty.

2. New approaches to cardiac failure:

-the use of ACE-inhibitors.

-the use of low dose beta-blockers.

-new pacing and electrophysiological techniques.

-effective antiarrhythmic drugs: amiodarone and flecainide.

3. Recognition of the frequency and significance of atrial fibrillation:

-increased use of anticoagulation in atrial fibrillation.

HEART FAILURE

Critical nursing tasks in acute left heart failure:
-Ensure adequate oxygenation.
-Measure the blood pressure.
-Evaluate the pulse.
Important nursing tasks in acute left heart failure:
-Ensure compliance with continuous oxygen.
-Assess the response to diuretics.
-Look for symptomatic improvement.
-Demonstrate normalisation of the pulse and blood pressure.

Acute on chronic congestive cardiac failure: the main clinical features are bilateral ankle oedema, debilitating tiredness and breathlessness on exertion.

Important nursing tasks in congestive cardiac failure:

-Identify posible causes of cardiac failure (uncontrolled hypertension, ischaemic heart disease, alcohol-induced cardiac failure, chronic rheumatic valve disease)

-Establish the exact preadmission drug regimen.

-Recognise significant hypotension.

-Assess the lower limbs and pressure areas.

-Assess the fluid balance (Symptoms and signs of congestion, symptoms and signs of fluid depletion).

ISCHAEMIC HEART DISEASE

Chest pain: commonly used descriptions in angina include pressure, weight, chest tightness and constriction. Patients often also describe a feeling of breathlessness. Serious anginal episodes are accompanied by pallor, sweating and hypotension. Prolonged pain (lasting more than 15 min), especially if it is accompanied by nausea and vomiting, is more in-keeping with an infarction than with angina, although the distinction can be difficult.

Ischaemic heart disease occurs when the enlargement of cholesterol-rich plaques within the coronary artery walls lead to arterial narrowing, which is sufficient to starve the heart muscle of oxygen. Slow progressive narrowing results in stable angina. However if plaque becomes unstable and ruptures, there is a sudden combination of platelet clumping and thrombosis which clots off the coronary artery. The resulting clinical conditions are termed Acute Coronary Syndromes (ACS). There are three types of ACS dependant on the extent of the blockage and the degree of resulting heart muscle damage: STEMI, NSTEMI and unstable angina.  

Critical nursing tasks in the patient with chest pain:

-ABC triage.

-Monitor oxygen saturation.

-Obtain a 12-lead ECG.

-Take an overall look at the patient.

-Ask key questions (where id the pain? what makes it worse a what relieves it? has it occurred before?).

ATRIAL FIBRILLATION AND ARTERIAL EMBOLI
In atrial fibrillation, organised atrial activity is replaced by random electrical impulses which spread chaotically through the atrium. The atrium responds by muscular activity that can be described as a shivering motion (fibrillation), rather than a coordinated contraction. There are two important consequences:
-The atrial "squeeze", which expels the final 10% of blood into the ventricle at the end of diastole, is lost.
-The AV node is activated at random by the chaotic atrial electrical activity at rates of anything between 60 and 140 times per minute. An irregular rate of 140beats/min will not be tolerated by the heart for long.
Also, atrial fibrillation reduces cardiac output due to loss of atrial contraction, ventricular response too rapid and irregular ventricular rate.

Critical nursing tasks in atrial fibrillation:
-Assess the rate of fibrillation.
-Identify chest pain.
-Look for heart failure.
-Document hypotension.
Important nursing tasks in atrial fibrillation:
-Observe for emboli (brain, limbs, intestine).
-Look for non-cardiac triggers (pneumonia, COPD exacerbations and sepsis).
-Obtain an accurate drug history.

INFECTIVE ENDOCARDITIS
Infective endocarditis is a serious condition in which there is infection of the heart valves, usually the mitral or aortic valve. The affected valve may fail suddenly as it is destroyed by infection. Pieces of infected material can break off and spread via the blood to vital organs, resulting in:
-foci of sepsis, especially in the kidneys.
-septic cerebral emboli (stroke-like illness).

How infective endocarditis presents:
-Pyrexia of unknown origin.
-Catastrophic valve failure.
-Infected emboli.

Principles of management in the first 24h.
1. Ensure the safety of the patient.
2. Secure the diagnosis.
3. Initiate antibiotic therapy: prepare the patient for a "long haul" of antibiotic therapy (several weeks).
4. Observe for complications: allergies, left heart failure, monitor temperature and urine output and look for septic emboli.

Source:
-A nurse´s survival guide to acute medical emergencies, R. Harrison and L. Daly, Elsevier 2011.