Differential Diagnosis
The patient's symptoms of progressive exertional breathlessness, orthopnea, paroxysmal nocturnal dyspnea, bilateral pedal edema, tachycardia, gallop rhythm, and fine basal crackles suggest a diagnosis related to heart failure. Here's a categorized differential diagnosis:
Single most likely diagnosis:
- Heart Failure with Reduced Ejection Fraction (HFrEF): The patient's symptoms and signs, such as exertional breathlessness, orthopnea, paroxysmal nocturnal dyspnea, and fine basal crackles, are classic for heart failure. The history of chronic smoking increases the risk of coronary artery disease, which can lead to HFrEF.
Other Likely diagnoses:
- Chronic Obstructive Pulmonary Disease (COPD) with Cor Pulmonale: Although the patient's symptoms could be attributed to COPD, the presence of orthopnea, paroxysmal nocturnal dyspnea, and gallop rhythm suggests a cardiac component.
- Hypertensive Heart Disease: Uncontrolled hypertension can lead to heart failure, and the patient's symptoms are consistent with this diagnosis.
- Coronary Artery Disease: The patient's history of smoking increases the risk of coronary artery disease, which can lead to heart failure.
Do Not Miss (ddxs that may not be likely, but would be deadly if missed.):
- Pulmonary Embolism: Although less likely, pulmonary embolism can cause sudden onset of breathlessness and can be fatal if missed.
- Cardiac Tamponade: This condition can cause breathlessness, orthopnea, and tachycardia, and is a medical emergency.
Rare diagnoses:
- Constrictive Pericarditis: This condition can cause heart failure-like symptoms, but is less common.
- Restrictive Cardiomyopathy: This condition can cause heart failure symptoms, but is less common than other forms of cardiomyopathy.
Diagnostic Investigations
To confirm the diagnosis, the following investigations can be performed:
- Chest X-ray to assess for cardiomegaly and pulmonary edema
- Electrocardiogram (ECG) to assess for signs of ischemia or arrhythmias
- Echocardiogram to assess left ventricular function and rule out other causes of heart failure
- Blood tests to assess for biomarkers of heart failure, such as BNP or NT-proBNP
- Pulmonary function tests to assess for COPD
Treatment
The treatment of the patient will depend on the underlying diagnosis. For heart failure with reduced ejection fraction, treatment may include:
- ACE inhibitors or ARBs to reduce afterload and improve cardiac function
- Beta blockers to reduce sympathetic tone and improve cardiac function
- Diuretics to reduce fluid overload and alleviate symptoms
- Aldosterone antagonists to reduce mortality and morbidity
- Lifestyle modifications, such as smoking cessation, exercise, and dietary changes.