title: Impact of the high-frequency cutoff of bandpass filtering on ECG quality and clinical interpretation: A comparison between 40Hz and 150Hz cutoff in a surgical preoperative adult outpatient population.
abstract: In 1990 the American Heart Association (AHA) established a standard 0.05 to 150Hz bandwidth for the routine recording of 12-lead electrocardiograms (ECGs). However, subsequent studies have indicated a very high prevalence of deviations from the recommended cutoffs.
  
  
  
  This prospective observational study investigates the impact of 40Hz compared to 150Hz high-frequency cutoffs on ECG quality and clinical interpretation in a single-center surgical outpatient population.
  
  
  
  1582 consecutive adult patients underwent two standard 12-lead ECG tracings using different high-frequency cutoffs (40Hz and 150Hz). Two blinded cardiologists randomly reviewed and interpreted the recordings according to pre-defined parameters (PR and ST segment, Q and T wave abnormalities). An arbitrary score, ranging from 1 to 3, was established to evaluate the perceived quality of the recordings and the non-interpretable ECGs were noted. The tracings were then matched to compare interpretations between 40 and 150Hz filters.
  
  
  
  A 40Hz high-frequency cutoff resulted in an increased rate of optimal quality ECGs compared to the 150Hz cutoff (93.4% vs 54.6%; p<0.001) and a lower rate of non-interpretable traces (0.25% vs 4.80%; p<0.001). Analyzing the morphologic parameters, no significant differences between the filter settings were found, except for a higher incidence of the J-point elevation in the 40Hz high-frequency cutoff (p=0.007) and a higher incidence of left ventricular hypertrophy in the 150Hz high-frequency cutoff (7.4% vs 5.4%, p<0.001). The latter was noted only in ECGs with borderline QRS amplitudes (between 3.3 and 3.7mV; p<0.001).
  
  
  
  Despite current recommendations, the large deviation from standard high-frequency cutoff in clinical practice does not seem to significantly affect ECG clinical interpretation and a 40Hz high-frequency cutoff of the band-pass filtering may be acceptable in a low risk population, allowing for a better quality of tracings.
authors: Cardiovascular Sciences Department, Campus Bio-Medico University of Rome, Via Alvaro del Portillo 200, 00128 Rome, Italy. Electronic address: d.ricciardi@unicampus.it.
authors: Danilo
authors: D
authors: Ricciardi
authors: Cardiovascular Sciences Department, Campus Bio-Medico University of Rome, Via Alvaro del Portillo 200, 00128 Rome, Italy.
authors: Ilaria
authors: I
authors: Cavallari
authors: Cardiovascular Sciences Department, Campus Bio-Medico University of Rome, Via Alvaro del Portillo 200, 00128 Rome, Italy.
authors: Antonio
authors: A
authors: Creta
authors: Cardiovascular Sciences Department, Campus Bio-Medico University of Rome, Via Alvaro del Portillo 200, 00128 Rome, Italy.
authors: Giacomo
authors: G
authors: Di Giovanni
authors: Cardiovascular Sciences Department, Campus Bio-Medico University of Rome, Via Alvaro del Portillo 200, 00128 Rome, Italy.
authors: Vito
authors: V
authors: Calabrese
authors: Cardiology Division, Ospedali Riuniti Anzio-Nettuno, Via Cupa dei Marmi, 00042 Anzio, Rome, Italy.
authors: Natale
authors: N
authors: Di Belardino
authors: Cardiovascular Sciences Department, Campus Bio-Medico University of Rome, Via Alvaro del Portillo 200, 00128 Rome, Italy.
authors: Simona
authors: S
authors: Mega
authors: Cardiovascular Sciences Department, Campus Bio-Medico University of Rome, Via Alvaro del Portillo 200, 00128 Rome, Italy.
authors: Iginio
authors: I
authors: Colaiori
authors: Cardiovascular Sciences Department, Campus Bio-Medico University of Rome, Via Alvaro del Portillo 200, 00128 Rome, Italy.
authors: Laura
authors: L
authors: Ragni
authors: Cardiovascular Sciences Department, Campus Bio-Medico University of Rome, Via Alvaro del Portillo 200, 00128 Rome, Italy.
authors: Claudio
authors: C
authors: Proscia
authors: Cardiovascular Sciences Department, Campus Bio-Medico University of Rome, Via Alvaro del Portillo 200, 00128 Rome, Italy.
authors: Antonio
authors: A
authors: Nenna
authors: Cardiovascular Sciences Department, Campus Bio-Medico University of Rome, Via Alvaro del Portillo 200, 00128 Rome, Italy.
authors: Germano
authors: G
authors: Di Sciascio
mesh_terms: D000328:Adult; D000553:Ambulatory Care / Q000706:statistics & numerical data; D001145:Arrhythmias, Cardiac / Q000175:diagnosis* / Q000453:epidemiology*; D003936:Diagnosis, Computer-Assisted; D004562:Electrocardiography / Q000295:instrumentation* / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D007558:Italy / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D057234:Preoperative Period; D015995:Prevalence; D011446:Prospective Studies; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012815:Signal Processing, Computer-Assisted; D016037:Single-Blind Method
keywords: Digital signal processing; ECG; High-frequency ECG filtering; Left ventricular hypertrophy