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  2. Premature ventricular contraction - Wikipedia

    en.wikipedia.org/wiki/Premature_ventricular...

    A premature ventricular contraction (PVC) is a common event where the heartbeat is initiated by Purkinje fibers in the ventricles rather than by the sinoatrial node. PVCs may cause no symptoms or may be perceived as a "skipped beat" or felt as palpitations in the chest. PVCs do not usually pose any danger. [1]

  3. Ectopic beat - Wikipedia

    en.wikipedia.org/wiki/Ectopic_beat

    Ectopic beat is a disturbance of the cardiac rhythm frequently related to the electrical conduction system of the heart, in which beats arise from fibers or group of fibers outside the region in the heart muscle ordinarily responsible for impulse formation (i.e., the sinoatrial node).

  4. Concealed conduction - Wikipedia

    en.wikipedia.org/wiki/Concealed_conduction

    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 node. However, this AV node stimulation can cause a delay in subsequent AV conduction by modifying ...

  5. Premature heart beat - Wikipedia

    en.wikipedia.org/wiki/Premature_heart_beat

    A premature heart beat or extrasystole [1] is a heart rhythm disorder corresponding to a premature contraction of one of the chambers of the heart. Premature heart beats come in two different types: premature atrial contractions and premature ventricular contractions. Often they cause no symptoms but may present with fluttering in the chest or ...

  6. Left axis deviation - Wikipedia

    en.wikipedia.org/wiki/Left_axis_deviation

    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°.

  7. Pulmonary valve stenosis - Wikipedia

    en.wikipedia.org/wiki/Pulmonary_valve_stenosis

    [1] [5] While the most common cause of pulmonary valve stenosis is congenital heart disease , it may also be due to a malignant carcinoid tumor. Both stenosis of the pulmonary artery and pulmonary valve stenosis are forms of pulmonic stenosis (nonvalvular and valvular, respectively) [ 6 ] but pulmonary valve stenosis accounts for 80% of ...

  8. Cardiac Arrhythmia Suppression Trial - Wikipedia

    en.wikipedia.org/wiki/Cardiac_Arrhythmia...

    The second Cardiac Arrhythmia Suppression Trial (CAST II) modified the enrollment criteria to include patients at higher risk for serious arrhythmia. [4] This included 1) patients enrolled within 4 to 90 days of a previous MI, 2) a left ventricular ejection fraction lower than 40%, 3) prior to enrollment, suppression of PVCs had occurred with the drugs (vs. placebo) using a double-blinded ...

  9. Hypertrophic cardiomyopathy - Wikipedia

    en.wikipedia.org/wiki/Hypertrophic_cardiomyopathy

    In individuals with aortic stenosis, after a premature ventricular contraction (PVC), the following ventricular contraction will be more forceful, and the pressure generated in the left ventricle will be higher. Because of the fixed obstruction that the stenotic aortic valve represents, the post-PVC ascending aortic pressure will increase as well.