Acute Left Ventricular Failure

Acute Left Ventricular Failure.

Acute left ventricular failure presents as pulmonary oedema due to increased pressure in the pulmonary capillaries. But left ventricular failure and pulmonary oedema are not always synonymous. Acute heart failure may be decompensation of chronic heart failure. (Anonymous, 2006 )

Causes of Acute LVF

• Acute myocardial infarction or ischemia

• Aortic stenosis or aortic incompetence

• Hypertension

• Mitral incompetence

• Drugs e.g. beta blockers, cocaine

• Infection e.g. Myocarditis.

• Volume overload.

• Anemia.

• Hyperthyroidism.

Signs and symptoms

• Fatigue.

• Pulmonary oedema.

• Dyspnoea - Paroxysmal nocturnal dyspnea.

• Cough.

• Crepitations - after coughing.

• Tachycardia.

• Hypoxia & cyanosis.

• Sweating.

• Cardiomegaly - X ray.
  
  
• Dilated pulmonary capillaries and upper lobe diversion - X ray.

• Gallup rhythm - a third heart sound and/or a fourth heart sound.

• Orthopnoea.

Signs and symptoms of ALVF

( http://img2.tfd.com/mk/H/X2604-H-14.png )

Investigations

1. ECG

2. Echo cardiograph - The echo cardiograph is the most frequently used investigation. Echo cardiography is the key test to provide a semi-objective assessment of cardiac function. It enables an assessment of:

                        Overall LV systolic function

                        Diastolic function

                        LV wall thickness

                        Valvular diseases.

                        Estimation of pulmonary artery systolic pressure.

3. Serum natriuretic peptides (B‑type natriuretic peptide [BNP] - -  If Acute LVF BNP is more than 100 mg/liter.

4. N‑terminal pro‑B‑type natriuretic peptide [NT‑proBNP] – If acute LVF NT‑proBNP is more than 300 mg/liter.

( In people presenting with new suspected acute heart failure with raised natriuretic peptide levels, perform trans thoracic Doppler 2D echo cardiography to establish the presence or absence of cardiac abnormalities. ) (NICE guidelines, 2014) 

5. Blood tests - FBC, U&E and creatinine, glucose, fasting lipids, thyroid function test

.

6. CXR – Chest X Ray provides details of 

                        Cardiomegaly (cardio thoracic ratio >50%)

                        Ventricular hypertrophy

                        Peribronchial cuffing.

                        Fluid in the fissures

                        Pleural effusions

CXR - ( http://upload.wikimedia.org/wikipedia/commons/1/1c/PulmEdema.PNG )

7. Urinalysis.

8. Lung function tests (peak flow or spirometry).

9. Cardiac magnetic resonance imaging - For assessing ventricular volumes, mass and wall motion. It can be used with contrast to identify inflammation, infiltration and scarring of the myocardium. ( (Kavanagh, 2012).

Management

Initial Management

The patient should be sitting upright and assessed by the ABC approach.

          A -  Check the patient’s airway and administer high flow oxygen through a reservoir bag (also known as trauma mask).

          B - Monitor the patient’s breathing and look for evidence of fatigue (if concerns then an urgent anesthetic/ICU opinion should be sought). Pulse oximetry should be used.

          C - Assess the patient’s circulation by measuring pulse and blood pressure and feeling their peripheries to check perfusion. The patient should be on a cardiac monitor to identify any arrhythmia s. Insert an intravenous cannula.

Immediate management

Morphine IV as required – this will help allay the terror and anxiety but may also reduce preload and after load Oxygen.

Drug therapy

• Intravenous diuretic (frusemide), venodilator (isosorbide dinitrate), arteriolar dilator (hydralazine), and positive inotropic stimulation (prenalterol) as first-line therapy for acute left ventricular failure.

• Second line treatments include dobutamine, especially if the systolic blood pressure is below l00mmHg. Bronchodilators such as beta -2 agonists or aminophylline may be used if wheezing is present - 'cardiac asthma'. (Verma SP, Silke B, Hussain M, Nelson GI, Reynolds GW, Richmond A, Taylor SH., 1987) 

1. Diuretics: help by reducing circulatory volume and thereby reducing preload. An intravenous loop diuretic such as Frusemide is administered in the first instance (Frusemide).

2. Venodilators: an intravenous infusion of Glceryl Trinitrate may be useful in reducing preload and after load and may also improve coronary blood flow.

3. Inotropic drugs: these drugs are used to increase myocardial contractility and output. They are often classified according to their activity at alpha and beta receptors.

4. Dobutamine : Exerts its effects on beta 1 and beta 2 receptors and thereby Increases myocardial contractility and output.

5. Dopamine : Exerts its effects on dopaminergic, beta 1 and beta 2 receptors. At low dose (0.5 - 2 mcgs/Kg/min) it has mainly dopaminergic effects ~ increased renal blood flow and diuresis.

6. ACE Inhibitors : ACE inhibitors have been shown to reduce symptoms and signs of heart failure, and improve exercise capacity. Renal function and serum potassium must be monitored before initiation.

7. Spironolactone : Patients with severe heart failure and left ventricular systolic dysfunction should be treated with low dose spironolactone (25mg ) unless there are contra indications. Monitoring of serum potassium is mandatory.

Management of ALVF

( http://eurheartj.oxfordjournals.org/content/ehj/29/19/2388/F7.large.jpg)

Non-pharmacological interventions

1. Diet   

         Salt - Dietary salt should be reduced as much as possible by avoiding the intake of salt rich foods.

         Fluid intake - Excessive fluid intake should be avoided.

         Obesity - Obesity should be reduced. Patients should be advised about setting realistic targets to reduce body weight. This will require counselling about behaviour change as well as nutritional advise. 

 2. Alcohol  - Alcohol should be avoided completely in patients with alcohol induced cardiomyopathy. In other patients with heart failure, alcohol can be consumed in small amounts.

3. Smoking - Patients should be advised to stop smoking and their readiness to do so assessed.

4. Exercise - Appropriate exercise is beneficial for patients with stable heart failure and structured programmes for patients with heart failure, including long term maintenance, are to be developed in the future.

REFERENCES

• Anonymous. (2006 , august 14). Acute Left Ventricular Failure (LVF). Retrieved April 28, 2015, from www.skills4nurses.com: http://www.skills4nurses.com/index.cgi?article+146

• Anonymous. (2013). acute left ventricular failure. Retrieved April 28, 2015, from www.gpnotebook.co.uk: http://www.gpnotebook.co.uk/simplepage.cfm?ID=-778436541

• Kavanagh, S. (2012, 07 29). Heart Failure Diagnosis and Investigation. Retrieved 04 28, 2015, from http://www.patient.co.uk/: http://www.patient.co.uk/doctor/heart-failure-diagnosis-and-investigation

• Verma SP, Silke B, Hussain M, Nelson GI, Reynolds GW, Richmond A, Taylor SH. (1987, July 10). First-line treatment of left ventricular failure complicating acute myocardial infarction: a randomised evaluation of immediate effects of diuretic, venodilator, arteriodilator, and positive inotropic drugs on left ventricular function. Retrieved april 28, 2015, from pubmed: http://www.ncbi.nlm.nih.gov/pubmed/2441152