Search results
Results from the WOW.Com Content Network
Premature ventricular contraction in an ECG (arrows) of a dog, caused by dilated cardiomyopathy. Premature ventricular contractions occur in healthy persons of any age, but are more prevalent in the elderly and in men. [3] In a very significant proportion of people they occur spontaneously with no known cause. [citation needed]
The term "concealed" is in reference to that the conduction is not observable by electrocardiogram. A common example would be an interpolated PVC (a type of premature ventricular contraction) during normal sinus rhythm; the PVC does not cause an atrial contraction, because the retrograde impulse from the PVC does not completely penetrate the AV ...
Bigeminy is a cardiac arrhythmia in which there is a single ectopic beat, or irregular heartbeat, following each regular heartbeat.Most often this is due to ectopic beats occurring so frequently that there is one after each sinus beat, or normal heartbeat.
While studying PVC characteristics, Schmidt and his colleagues noticed that heart rate seemed to speed up after a PVC. To clarify, they listed the time from one heartbeat's R-wave to the next R-wave (called RR intervals) and synchronized these lists to the time of the PVC beat and averaged the values in the list. A plot of this averaged RR ...
This results in much greater LV pressures than the aortic pressures during LV ejection. The magnitude of the pressure gradient is determined by the severity of the stenosis and the flow rate across the valve. Severe aortic stenosis results in reduced ventricular stroke volume due to increased afterload (which decreases ejection velocity)
Electrocardiography (ECG/EKG in German vernacular. Elektrokardiogram) monitors electrical activity of the heart, primarily as recorded from the skin surface. A 12 lead recording, recording the electrical activity in three planes, anterior, posterior, and lateral is the most commonly used form.
The hexaxial reference system is a diagram that is used to determine the heart's electrical axis in the frontal plane.. In electrocardiography, left axis deviation (LAD) is a condition wherein the mean electrical axis of ventricular contraction of the heart lies in a frontal plane direction between −30° and −90°.
The height of AC component of the photoplethysmogram is proportional to the pulse pressure, the difference between the systolic and diastolic pressure in the arteries. As seen in the figure showing premature ventricular contractions (PVCs), the PPG pulse for the cardiac cycle with the PVC results in lower amplitude blood pressure and a PPG.