Differential Diagnosis for Low Diastolic Blood Pressure

The patient's presentation of low diastolic blood pressure, in conjunction with other symptoms and medical history, warrants a comprehensive differential diagnosis. The following categories outline potential causes:

• Single Most Likely Diagnosis

  • Deconditioning and decreased intravascular volume: Given the patient's significant weight loss (50 lbs in 2 years), sedentary lifestyle, and diagnosis of CHF with a relatively preserved EF (65%), it's plausible that her low diastolic blood pressure is a result of decreased intravascular volume and deconditioning. This is further supported by the absence of postural hypotension but a notable drop in blood pressure when not on antihypertensives.

• Other Likely Diagnoses

  • Autonomic dysfunction: The patient's history of peripheral neuropathy and essential tremors, along with the presence of tongue fasciculations, suggests possible autonomic nervous system involvement, which could contribute to blood pressure dysregulation.
  • Diabetes-related autonomic neuropathy: As a patient with type 2 diabetes, there's a risk of developing autonomic neuropathy, which can affect blood pressure control.
  • Overly aggressive treatment of hypertension: The recent cessation of antihypertensive medications (spironolactone and telmisartan) due to low diastolic blood pressure readings may indicate that the treatment was too aggressive for the patient's current condition.

• Do Not Miss Diagnoses

  • Amyloidosis: Although rare, amyloidosis can cause autonomic dysfunction leading to orthostatic hypotension and could be considered given the patient's complex presentation, including peripheral neuropathy and essential tremors. The high ANA readings without a clear autoimmune diagnosis also warrant consideration of less common conditions.
  • Multiple System Atrophy (MSA): This is a rare neurodegenerative disorder that can present with autonomic dysfunction, including orthostatic hypotension, and could be a consideration given the patient's neurological symptoms.

• Rare Diagnoses

  • Pheochromocytoma with predominant parasympathetic response: Although typically associated with hypertension, in rare cases, pheochromocytomas can cause hypotension due to a predominant parasympathetic response or intermittent secretion of catecholamines.
  • Adrenal insufficiency: This condition can lead to hypotension and might be considered, especially if there are other signs of adrenal dysfunction, though it seems less likely given the patient's current presentation and lack of specific symptoms pointing towards adrenal insufficiency.

Given the patient's complex medical history and the recent diagnosis of CHF with a preserved EF, careful consideration of her volume status, autonomic function, and the potential for over-treatment of hypertension is necessary. Reinitiating antihypertensive therapy may not be immediately necessary but should be guided by close monitoring of her blood pressure and clinical status. Further evaluation of her autonomic nervous system function and consideration of less common causes of her symptoms may also be warranted.