Diaphragmatic Flutter Can Be Unilateral
Yes, diaphragmatic flutter can occur unilaterally, affecting only one hemidiaphragm, though the condition is more commonly bilateral. The literature describes cases where flutter involves one side of the diaphragm, and the laterality depends on the underlying etiology and mechanism of the disorder.
Clinical Presentation and Laterality
Diaphragmatic flutter manifests as rapid rhythmic involuntary contractions of the diaphragm, typically at frequencies ranging from 0.5-8.0 Hz in classic cases, though higher frequencies (9-15 Hz) have been documented 1.
Unilateral involvement can occur, particularly in cases related to traumatic injury or structural abnormalities affecting one hemidiaphragm 2, 3.
Traumatic diaphragmatic injury from blunt or penetrating trauma can create defects that alter normal contractile patterns on the affected side, potentially leading to unilateral flutter 2.
Diaphragm contusion (AAST Grade I injury) can cause localized dysfunction affecting only one hemidiaphragm 2.
Diagnostic Considerations
The diagnosis is established through electromyography (EMG) of the diaphragm, which demonstrates repetitive discharges at characteristic frequencies 1.
Spirographic tracings showing high-frequency oscillations superimposed on tidal respiratory movements help confirm the diagnosis 1.
When evaluating suspected unilateral diaphragmatic pathology, ultrasound can detect abnormal contractile patterns and distinguish between flutter and paralysis 4.
Etiologic Diversity
The etiology of diaphragmatic flutter is diverse and includes metabolic causes (hypocalcemia), neurologic conditions (striatal necrosis), traumatic injury, and idiopathic cases 5, 2.
Unilateral cases are more likely associated with structural or traumatic causes affecting one hemidiaphragm, while bilateral cases may reflect systemic metabolic or neurologic etiologies 5, 2.
Treatment Implications
Treatment depends on the underlying cause: calcium for hypocalcemia, carbamazepine (200-400 mg three times daily) for idiopathic high-frequency flutter, or noninvasive ventilatory support for refractory cases 1, 6, 5.
For unilateral flutter related to trauma, addressing the structural defect may be necessary, while metabolic causes require correction of the underlying abnormality 2, 5.
Phrenic nerve crush has been used successfully in severe cases, though this approach would typically be reserved for the affected side in unilateral disease 7.