Acute Coronary Syndrome (ACS): Given the patient's age, history of hypertension, and presenting symptom of chest heaviness, ACS (which includes myocardial infarction and unstable angina) is the most likely diagnosis. Hypertension is a significant risk factor for coronary artery disease, and chest heaviness is a common symptom of ACS.

Gastroesophageal Reflux Disease (GERD): GERD can cause chest discomfort or heaviness, especially after eating or at night, and is common in the general population. The symptoms can sometimes be confused with cardiac issues.
Anxiety or Panic Disorder: These conditions can manifest with chest discomfort or a feeling of heaviness, among other symptoms like shortness of breath, palpitations, and fear of dying. Given the psychological impact of chronic conditions like hypertension, this is a plausible differential.
Pulmonary Embolism (PE): Although less common than ACS, PE is a significant consideration, especially if the patient has risk factors such as recent immobilization, cancer, or genetic predispositions. It can present with sudden onset of chest pain or discomfort.

Aortic Dissection: This is a life-threatening condition where there is a tear in the aorta's inner layer. It can present with sudden, severe chest pain or discomfort that may radiate to the back. Given the patient's history of hypertension (a major risk factor for aortic dissection), it's crucial not to miss this diagnosis.
Pneumonia: Especially if the patient has a fever, cough, or shortness of breath in addition to chest heaviness. Pneumonia can lead to severe complications if not promptly treated.
Pericarditis: Inflammation of the pericardium, the sac surrounding the heart, can cause chest pain that may be confused with ACS. It's less common but can be serious, especially if it leads to cardiac tamponade.

Esophageal Spasm or Esophageal Rupture: These conditions can cause severe chest pain but are less common. Esophageal rupture is a medical emergency.
Hypertrophic Cardiomyopathy: A condition where the heart muscle becomes abnormally thick, which can lead to chest pain, shortness of breath, and fainting. It's less common and often associated with specific physical examination findings or family history.
Mitral Valve Prolapse: Can cause chest discomfort, but it's usually associated with a midsystolic click and late systolic murmur on physical examination.