The first derivation of the Frank Lead ECG at alterations of pulmonary ventilation in young healthy women.
The Frank orthogonal corrected ECG and its first derivation were recorded in 27 healthy volunteers (women aged 19-22 years) during normal ventilation at rest (control group), after voluntary hyperventilation lasting 75 seconds, and during hypoxic-hypercapnic ventilation (through the enlarged dead space) lasting 5 min. The projections of the magnitude and direction of the positive and negative QRS derivation maxima into the horizontal, frontal, left sagittal planes and their spatial distribution were constructed. The magnitude of the positive and negative QRS derivation maxima was significantly decreased during hypoxic-hypercapnic ventilation. A significant alteration in the direction only arose at the positive maximum during hypoxic-hypercapnic ventilation in the frontal plane. The intrinsicoid deflection was not significantly altered. The normal values of the maxima of the first QRS derivation in young healthy women are given. It is supposed that the decrease in amplitude of the maxima of the first QRS derivation is caused by slowed propagation of the depolarization wave under hypoxic-hypercapnic conditions and alteration of the direction of the positive maximum is caused by a greater participation of the right ventricle at the origin of the resulting QRS vector.
Kujaník
S
S
Department of Physiology, Safárik University, Kosice, Slovak Republic.
Baldovský
L
L
Bohus
B
B
D000328:Adult; D004562:Electrocardiography; D005260:Female; D006801:Humans; D006935:Hypercapnia / Q000503:physiopathology; D006985:Hyperventilation / Q000503:physiopathology; D000860:Hypoxia / Q000503:physiopathology; D012016:Reference Values; D012119:Respiration / Q000502:physiology*; D012146:Rest