What is the treatment for a 55-year-old man with hypertension (high blood pressure), chest pain, and radiating pain to the left shoulder, tachycardia (pulse of 124 beats per minute), and an electrocardiogram (ECG) showing an abnormal long QT interval?

Differential Diagnosis for a 55-year-old Man with Hypertension, Chest Pain, and Abnormal ECG

Single Most Likely Diagnosis

• Acute Coronary Syndrome (ACS): The combination of chest pain, hypertension (170/98 mmHg), and an abnormal ECG with a long QT interval in a 55-year-old man strongly suggests ACS, which includes conditions such as myocardial infarction (MI). The long QT interval can be a marker of myocardial ischemia or a side effect of certain medications but is also a risk factor for torsades de pointes, a potentially fatal arrhythmia.

Other Likely Diagnoses

• Hypertensive Emergency: Given the high blood pressure (170/98 mmHg) and chest pain, a hypertensive emergency, which could involve acute heart failure, aortic dissection, or pulmonary edema, should be considered.
• Aortic Dissection: Although less common, the combination of severe chest pain, high blood pressure, and radiation of pain to the left shoulder could indicate an aortic dissection, especially if the pain is described as tearing or ripping.
• Pulmonary Embolism: While the presentation is more typical of cardiac issues, pulmonary embolism can cause chest pain, tachycardia (124 beats per minute), and could potentially lead to ECG changes, including a long QT interval in some cases.

Do Not Miss Diagnoses

• Cardiac Tamponade: Although less likely, cardiac tamponade can cause chest pain, tachycardia, and hypotension (though not present here), and can lead to ECG changes. It's a life-threatening condition that requires immediate intervention.
• Torsades de Pointes: Given the long QT interval, torsades de pointes, a specific type of abnormal heart rhythm that can be life-threatening, must be considered and promptly treated if identified.

Rare Diagnoses

• Mitral Valve Prolapse with Severe Mitral Regurgitation: This condition can cause chest pain and ECG abnormalities but is less likely given the acute presentation and other symptoms.
• Pericarditis: Inflammation of the pericardium can cause chest pain and ECG changes, including a long QT interval in some cases, but the overall clinical picture here makes it less likely.
• Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC): A rare condition that affects the heart muscle and can lead to abnormal heart rhythms and sudden death, but it's less likely given the acute presentation with hypertension and chest pain radiating to the shoulder.