Cocaine intoxication: The patient's symptoms of palpitations, anxiety, and significantly elevated blood pressure and pulse rate, combined with the history of smoking "crack" (a form of cocaine), strongly suggest cocaine intoxication as the most likely cause. Cocaine is a potent stimulant that can cause these cardiovascular and psychological effects.

Amphetamine or other stimulant intoxication: Although the patient was specifically reported to be smoking "crack," the possibility of using other stimulants either intentionally or unintentionally (e.g., contaminated substances) could also lead to similar symptoms.
Anxiety or panic disorder: The patient's symptoms of anxiety could be attributed to a primary psychiatric condition, but the presence of significantly elevated blood pressure and pulse, along with the history of substance use, makes this less likely as the primary cause.
Hypertensive emergency: The patient's blood pressure is significantly elevated, which could be due to various causes, including substance use. However, the context provided points more directly to an acute substance-induced cause rather than a primary hypertensive emergency.

Cardiac conditions (e.g., myocardial infarction, arrhythmias): Although less likely given the patient's age and the context of substance use, cardiac conditions can present with palpitations and anxiety. Missing a cardiac condition could be fatal, so it's crucial to consider and rule out these possibilities, especially with ECG findings.
Aortic dissection: This is a rare but potentially fatal condition that could be precipitated by severely elevated blood pressure. The patient's symptoms and blood pressure readings necessitate consideration of this diagnosis.
Pulmonary embolism: While less directly related to the symptoms described, any condition that causes significant anxiety and tachycardia could potentially be a pulmonary embolism, especially if there are other risk factors present.

Pheochromocytoma: A rare tumor of the adrenal gland that can cause episodic hypertension, tachycardia, and anxiety. While the patient's symptoms could fit this diagnosis, the context of recent substance use makes it less likely.
Thyroid storm: A life-threatening condition that can cause tachycardia, anxiety, and hypertension. It is less likely given the context but should be considered in the differential diagnosis of unexplained tachycardia and hypertension.
Neurological conditions (e.g., intracranial hemorrhage): Certain neurological emergencies can present with anxiety, tachycardia, and hypertension. While less likely given the patient's presentation and history, these conditions are critical to rule out due to their potential severity.