title: 12-lead Holter monitoring in diving and water sports: a preliminary investigation.
abstract: OBJECTIVE
  To demonstrate the utility of 12-lead Holter monitoring underwater.
  
  
  METHODS
  A Holter monitor, recording a 12-lead electrocardiogram (ECG) underwater, was applied to 16 pre-trained volunteer scuba divers (13 males and three females). Dive computers were synchronized with the Holter recorder to correlate the ECG tracings with diving events. Our main objective was to demonstrate the utility of recording over a period of time a good quality 12-lead ECG underwater. The ECGs were analyzed for heart rate (HR), arrhythmias, conduction abnormalities and ischaemic events in relation to various stages of diving as follows: baseline, pre diving, diving, and post diving.
  
  
  RESULTS
  The ECG tracings were of good quality with minimal artefacts. Analysis of variance (ANOVA) demonstrated a significant difference in HR during the various diving stages (P < 0.0001). Other recorded ECG abnormalities included supraventricular ectopic beats (four cases), ventricular ectopic beats (eight cases) and ventricular couplets (two cases). Conduction abnormalities included rate-dependent right and left bundle branch block; however, these findings were previously known in these divers. No evidence of ischaemia was seen.
  
  
  CONCLUSIONS
  Continuous 12-lead Holter monitoring underwater can produce good quality tracings. Further studies are necessary to assess its usefulness in divers at risk for or with known coronary artery disease, and its comparison with other forms of cardiac stress tests.
authors.affiliation: Physiological Laboratory, Department of Biomedical Sciences, University of Padova, Italy.
authors.forename: Gerardo
authors.initials: G
authors.lastname: Bosco
authors.affiliation: Scuola Superiore Sant'Anna, Pisa, Italy.
authors.forename: Elena
authors.initials: E
authors.lastname: De Marzi
authors.affiliation: Sports Medicine and Physical Activities Unit - "aiColli" Social Health Department, Padova, Italy.
authors.forename: Pierantonio
authors.initials: P
authors.lastname: Michieli
authors.affiliation: Internal Medicine Department, Mercy Hospital and Medical Center, Chicago, Illinois, USA.
authors.forename: Hesham R
authors.initials: HR
authors.lastname: Omar
authors.affiliation: Departments of Surgery/Anesthesiology and Molecular Pharmacology and Physiology, University of South Florida College of Medicine, Tampa General Hospital 1 Tampa General Circle Suite A327, Tampa, Florida, 33606, USA, E-mail: ecampore@health.usf.edu.
authors.forename: Enrico M
authors.initials: EM
authors.lastname: Camporesi
authors.affiliation: Physiological Laboratory, Department of Biomedical Sciences, University of Padova, Italy.
authors.forename: Johnny
authors.initials: J
authors.lastname: Padulo
authors.affiliation: Physiological Laboratory, Department of Biomedical Sciences, University of Padova, Italy.
authors.forename: Antonio
authors.initials: A
authors.lastname: Paoli
authors.affiliation: Florida Gulf to Bay Anesthesia, Tampa General Hospital, Tampa, Florida, USA.
authors.forename: Devanand
authors.initials: D
authors.lastname: Mangar
authors.affiliation: Scuola Superiore Sant'Anna, Pisa, Italy, Sports Medicine and Physical Activities Unit - "aiColli" Social Health Department, Padova, Italy.
authors.forename: Maurizio
authors.initials: M
authors.lastname: Schiavon
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D001145:Arrhythmias, Cardiac / Q000175:diagnosis / Q000503:physiopathology*; D004242:Diving / Q000502:physiology*; D004562:Electrocardiography; D015716:Electrocardiography, Ambulatory / Q000295:instrumentation*; D005260:Female; D005618:Fresh Water; D006329:Heart Conduction System / Q000502:physiology; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D007511:Ischemia / Q000175:diagnosis; D008297:Male; D008875:Middle Aged; D012623:Seawater; D013997:Time Factors; D055815:Young Adult
keywords: Scuba diving; cardiovascular; diving research; electrocardiography; pathology; patient monitoring; physiology