PURPOSE: Electrocardiographic (ECG) artifact is generally considered to be a nuisance. Respiratory artifact (RA), however, is a physiologic signal that may carry useful diagnostic information. The purpose of this study was to identify ECG RA and to correlate its rate and timing with the patient's clinical condition including dysrhythmia.
METHODS: 12-lead ECGs and telemetry strips were analyzed for the appearance of cyclic fuzzy artifact. The corresponding respiratory rates were identified by visual observation and plethysmography. The RA rate was correlated with clinical variables, and the temporal relationship between the presence of RA and major dysrhythmias was analyzed.
RESULTS: Fuzzy cyclic artifact, best seen in leads II and V5, was identified in 200 12-lead ECGs and 40 telemetry recordings. Visual observation and plethysmography linked the cyclic ECG artifact to the inspiratory cycle. Based on the RA rate, tachypnea was diagnosed on 180 occasions. In 4 patients with unexplained syncope, coughing artifact immediately preceding sudden sinus deceleration or AV block led to the diagnosis of cough syncope. In 10 patients evaluated for unexplained bradyarrhythmia, analysis of nocturnal RA indicated sleep disordered breathing. In 4/10 patients subsequently diagnosed with obstructive sleep apnea, telemetry strips revealed multiple episodes of sudden sinus deceleration, sinus pauses or AV block that coincided with the cyclic appearance of snoring artifact. In 6/10 patients later found to have central sleep apnea, telemetry strips revealed multiple episodes of profound sinus bradyarrhythmia or paroxysmal AV block followed by sudden acceleration of the heart rate. The abrupt increase in heart rate always coincided with the appearance of cyclic artifact representing choking or gasping tachypnea.
CONCLUSION: Respiratory artifacts are frequently present in 12-lead ECGs and rhythm strips. Analyzing the rate and pattern of the cycles and their relationship to heart rate and dysrhythmia may provide clues to the recognition of clinically important conditions such as tachypnea, cough syncope, obstructive and central sleep apnea.
CLINICAL IMPLICATIONS: RA in the ECG is a valuable diagnostic tool in the evaluation of respiratory distress and breathing-related dysrhythmias.
DISCLOSURE: Laszlo Littmann, No Financial Disclosure Information; No Product/Research Disclosure Information