Effect of mental challenge induced by movie clips on action potential duration in normal human subjects independent of heart rate.
BACKGROUND
Mental stress and emotion have long been associated with ventricular arrhythmias and sudden death in animal models and humans. The effect of mental challenge on ventricular action potential duration (APD) in conscious healthy humans has not been reported.


RESULTS
Activation recovery intervals measured from unipolar electrograms as a surrogate for APD (n=19) were recorded from right and left ventricular endocardium during steady-state pacing, whilst subjects watched an emotionally charged film clip. To assess the possible modulating role of altered respiration on APD, the subjects then repeated the same breathing pattern they had during the stress, but without the movie clip. Hemodynamic parameters (mean, systolic, and diastolic blood pressure, and rate of pressure increase) and respiration rate increased during the stressful part of the film clip (P=0.001). APD decreased during the stressful parts of the film clip, for example, for global right ventricular activation recovery interval at end of film clip 193.8 ms (SD, 14) versus 198.0 ms (SD, 13) during the matched breathing control (end film left ventricle 199.8 ms [SD, 16] versus control 201.6 ms [SD, 15]; P=0.004). Respiration rate increased during the stressful part of the film clip (by 2 breaths per minute) and was well matched in the respective control period without any hemodynamic or activation recovery interval changes.


CONCLUSIONS
Our results document for the first time direct recordings of the effect of a mental challenge protocol on ventricular APD in conscious humans. The effect of mental challenge on APD was not secondary to emotionally induced altered respiration or heart rate.
From the Department of Cardiology, Guy's and St. Thomas's Hospital, London, United Kingdom (N.C., C.A.R., J.B., M.C., M.O., M.W., R.R., J.G.); Department of Cardiovascular Imaging, Division of Imaging Sciences and Biomedical Engineering, King's College, London, United Kingdom (N.C., M.B., R.R.); Department of Mechanical Engineering, University College London, London, United Kingdom (B.H., D.W.); and Neurocardiology Unit, University College London Hospitals, London, United Kingdom (P.T.).
Nicholas
N
Child
From the Department of Cardiology, Guy's and St. Thomas's Hospital, London, United Kingdom (N.C., C.A.R., J.B., M.C., M.O., M.W., R.R., J.G.); Department of Cardiovascular Imaging, Division of Imaging Sciences and Biomedical Engineering, King's College, London, United Kingdom (N.C., M.B., R.R.); Department of Mechanical Engineering, University College London, London, United Kingdom (B.H., D.W.); and Neurocardiology Unit, University College London Hospitals, London, United Kingdom (P.T.).
Ben
B
Hanson
From the Department of Cardiology, Guy's and St. Thomas's Hospital, London, United Kingdom (N.C., C.A.R., J.B., M.C., M.O., M.W., R.R., J.G.); Department of Cardiovascular Imaging, Division of Imaging Sciences and Biomedical Engineering, King's College, London, United Kingdom (N.C., M.B., R.R.); Department of Mechanical Engineering, University College London, London, United Kingdom (B.H., D.W.); and Neurocardiology Unit, University College London Hospitals, London, United Kingdom (P.T.).
Martin
M
Bishop
From the Department of Cardiology, Guy's and St. Thomas's Hospital, London, United Kingdom (N.C., C.A.R., J.B., M.C., M.O., M.W., R.R., J.G.); Department of Cardiovascular Imaging, Division of Imaging Sciences and Biomedical Engineering, King's College, London, United Kingdom (N.C., M.B., R.R.); Department of Mechanical Engineering, University College London, London, United Kingdom (B.H., D.W.); and Neurocardiology Unit, University College London Hospitals, London, United Kingdom (P.T.).
Christopher A
CA
Rinaldi
From the Department of Cardiology, Guy's and St. Thomas's Hospital, London, United Kingdom (N.C., C.A.R., J.B., M.C., M.O., M.W., R.R., J.G.); Department of Cardiovascular Imaging, Division of Imaging Sciences and Biomedical Engineering, King's College, London, United Kingdom (N.C., M.B., R.R.); Department of Mechanical Engineering, University College London, London, United Kingdom (B.H., D.W.); and Neurocardiology Unit, University College London Hospitals, London, United Kingdom (P.T.).
Julian
J
Bostock
From the Department of Cardiology, Guy's and St. Thomas's Hospital, London, United Kingdom (N.C., C.A.R., J.B., M.C., M.O., M.W., R.R., J.G.); Department of Cardiovascular Imaging, Division of Imaging Sciences and Biomedical Engineering, King's College, London, United Kingdom (N.C., M.B., R.R.); Department of Mechanical Engineering, University College London, London, United Kingdom (B.H., D.W.); and Neurocardiology Unit, University College London Hospitals, London, United Kingdom (P.T.).
David
D
Western
From the Department of Cardiology, Guy's and St. Thomas's Hospital, London, United Kingdom (N.C., C.A.R., J.B., M.C., M.O., M.W., R.R., J.G.); Department of Cardiovascular Imaging, Division of Imaging Sciences and Biomedical Engineering, King's College, London, United Kingdom (N.C., M.B., R.R.); Department of Mechanical Engineering, University College London, London, United Kingdom (B.H., D.W.); and Neurocardiology Unit, University College London Hospitals, London, United Kingdom (P.T.).
Michael
M
Cooklin
From the Department of Cardiology, Guy's and St. Thomas's Hospital, London, United Kingdom (N.C., C.A.R., J.B., M.C., M.O., M.W., R.R., J.G.); Department of Cardiovascular Imaging, Division of Imaging Sciences and Biomedical Engineering, King's College, London, United Kingdom (N.C., M.B., R.R.); Department of Mechanical Engineering, University College London, London, United Kingdom (B.H., D.W.); and Neurocardiology Unit, University College London Hospitals, London, United Kingdom (P.T.).
Mark
M
O'Neil
From the Department of Cardiology, Guy's and St. Thomas's Hospital, London, United Kingdom (N.C., C.A.R., J.B., M.C., M.O., M.W., R.R., J.G.); Department of Cardiovascular Imaging, Division of Imaging Sciences and Biomedical Engineering, King's College, London, United Kingdom (N.C., M.B., R.R.); Department of Mechanical Engineering, University College London, London, United Kingdom (B.H., D.W.); and Neurocardiology Unit, University College London Hospitals, London, United Kingdom (P.T.).
Matthew
M
Wright
From the Department of Cardiology, Guy's and St. Thomas's Hospital, London, United Kingdom (N.C., C.A.R., J.B., M.C., M.O., M.W., R.R., J.G.); Department of Cardiovascular Imaging, Division of Imaging Sciences and Biomedical Engineering, King's College, London, United Kingdom (N.C., M.B., R.R.); Department of Mechanical Engineering, University College London, London, United Kingdom (B.H., D.W.); and Neurocardiology Unit, University College London Hospitals, London, United Kingdom (P.T.).
Reza
R
Razavi
From the Department of Cardiology, Guy's and St. Thomas's Hospital, London, United Kingdom (N.C., C.A.R., J.B., M.C., M.O., M.W., R.R., J.G.); Department of Cardiovascular Imaging, Division of Imaging Sciences and Biomedical Engineering, King's College, London, United Kingdom (N.C., M.B., R.R.); Department of Mechanical Engineering, University College London, London, United Kingdom (B.H., D.W.); and Neurocardiology Unit, University College London Hospitals, London, United Kingdom (P.T.).
Jaswinder
J
Gill
From the Department of Cardiology, Guy's and St. Thomas's Hospital, London, United Kingdom (N.C., C.A.R., J.B., M.C., M.O., M.W., R.R., J.G.); Department of Cardiovascular Imaging, Division of Imaging Sciences and Biomedical Engineering, King's College, London, United Kingdom (N.C., M.B., R.R.); Department of Mechanical Engineering, University College London, London, United Kingdom (B.H., D.W.); and Neurocardiology Unit, University College London Hospitals, London, United Kingdom (P.T.). peter.taggart@uclh.nhs.uk.
Peter
P
Taggart
D000200:Action Potentials / Q000502:physiology*; D000328:Adult; D000368:Aged; D001794:Blood Pressure / Q000502:physiology; D004562:Electrocardiography / Q000379:methods; D005260:Female; D006339:Heart Rate / Q000502:physiology*; D006439:Hemodynamics / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009040:Motion Pictures; D012016:Reference Values; D012494:Sampling Studies; D013315:Stress, Psychological; D017180:Tachycardia, Ventricular / Q000175:diagnosis / Q000523:psychology*; D016276:Ventricular Function / Q000502:physiology
action potentials; arrhythmias, cardiac; stress, psychological