Heart Failure Symptoms and Diagnosis

Introduction to Heart Failure Symptoms

The European Society of Cardiology considers Paroxysmal Nocturnal Dyspnea (DPN) as one of the typical symptoms of heart failure, characterized by episodes of severe respiratory distress occurring during sleep, waking the patient abruptly and requiring them to sit or stand to relieve symptoms 1, 2

The presence of DPN is useful for identifying patients with elevated pulmonary capillary pressure (≥18 mmHg), with a high negative predictive value (97-99%) for ruling out heart failure 1, 2, 3, 4
To evaluate DPN adequately, it is recommended to document the presence of dyspnea symptoms (exertional dyspnea, rest dyspnea, orthopnea, DPN, nocturnal cough in the supine position, tachypnea) and seek objective evidence of new or worsening heart failure, consisting of at least two physical examination findings or one physical examination finding and at least one laboratory criterion 5
Evaluating exercise tolerance and fatigue as accompanying symptoms is also crucial 5, 6
The persistence of DPN is associated with a higher rate of hospitalization during the 6-month follow-up after discharge 1, 2

The pathophysiology of DPN involves the redistribution of fluids, with approximately 250-500 cc of fluid moving from dependent venous reservoirs in the abdomen and lower extremities to the thoracic compartment when lying down, leading to increased venous and capillary pressures and pulmonary congestion 2
DPN may be associated with sleep apnea, which can contribute to hemodynamic worsening during the night, and the respiratory disturbance index is an independent factor associated with a history of DPN 1, 7
Patients with DPN are often men over 60 years old with atrial fibrillation and recurrent episodes of acute pulmonary edema 1, 7

It is essential to differentiate DPN from other causes of nocturnal dyspnea, such as obstructive sleep apnea, and from periodic breathing or Cheyne-Stokes respiration in patients with heart failure 1, 2
DPN is characterized by an episode of respiratory distress that occurs during sleep, wakes the patient abruptly, and requires the patient to sit or stand to relieve symptoms, differing from orthopnea, which is difficulty breathing in a supine position but appears before falling asleep 2
The presence of DPN has important implications, including the need for additional therapy if it persists despite treatment, and is part of the criteria for defining heart failure worsening events 4, 5, 8
DPN is a cardinal symptom of pulmonary congestion that requires immediate evaluation and treatment, as it may indicate worsening underlying heart failure and predict adverse events 2, 5, 8