P duration in ecg

https://med.libretexts.org/@app/auth/3/login?returnto=https%3A%2F%2Fmed.libretexts.org%2FBookshelves%2FAnatomy_and_Physiology%2FAnatomy_and_Physiology_(Boundless)%2F17%253A_Cardiovascular_System%253A_The_Heart%2F17.4%253A_Physiology_of_the_Heart%2F17.4B%253A_Electrocardiogram_and_Correlation_of_ECG_Waves_with_Systole \( \newcommand\) • • • • • • • An electrocardiogram, or ECG, is a recording of the heart’s electrical activity as a graph over a period of time. Key Points • An ECG is used to measure the rate and regularity of heartbeats as well as the size and position of the chambers, the presence of damage to the heart, and the effects of drugs or devices used to regulate the heart, such as a pacemaker. • The ECG device detects and amplifies the tiny electrical changes on the skin that are caused when the heart muscle depolarizes during each heartbeat, and then translates the electrical pulses of the heart into a graphic representation. • A typical ECG tracing of the cardiac cycle (heartbeat) consists of a P wave (atrial depolarization ), a QRS complex (ventricular depolarization), and a T wave (ventricular repolarization). An additional wave, the U wave ( Purkinje repolarization), is often visible, but not always. • The ST complex is usually elevated during a myocardial infarction. • Atrial fibrillation occurs when the P wave is missing and represents irregular, rapid, and inefficient atrial contraction, but is generally not fatal on its own. • Ventricular fibrillation oc...

https://med.libretexts.org/@app/auth/3/login?returnto=https%3A%2F%2Fmed.libretexts.org%2FBookshelves%2FAnatomy_and_Physiology%2FAnatomy_and_Physiology_(Boundless)%2F17%253A_Cardiovascular_System%253A_The_Heart%2F17.4%253A_Physiology_of_the_Heart%2F17.4B%253A_Electrocardiogram_and_Correlation_of_ECG_Waves_with_Systole \( \newcommand\) • • • • • • • An electrocardiogram, or ECG, is a recording of the heart’s electrical activity as a graph over a period of time. Key Points • An ECG is used to measure the rate and regularity of heartbeats as well as the size and position of the chambers, the presence of damage to the heart, and the effects of drugs or devices used to regulate the heart, such as a pacemaker. • The ECG device detects and amplifies the tiny electrical changes on the skin that are caused when the heart muscle depolarizes during each heartbeat, and then translates the electrical pulses of the heart into a graphic representation. • A typical ECG tracing of the cardiac cycle (heartbeat) consists of a P wave (atrial depolarization ), a QRS complex (ventricular depolarization), and a T wave (ventricular repolarization). An additional wave, the U wave ( Purkinje repolarization), is often visible, but not always. • The ST complex is usually elevated during a myocardial infarction. • Atrial fibrillation occurs when the P wave is missing and represents irregular, rapid, and inefficient atrial contraction, but is generally not fatal on its own. • Ventricular fibrillation oc...

https://med.libretexts.org/@app/auth/3/login?returnto=https%3A%2F%2Fmed.libretexts.org%2FBookshelves%2FAnatomy_and_Physiology%2FAnatomy_and_Physiology_(Boundless)%2F17%253A_Cardiovascular_System%253A_The_Heart%2F17.4%253A_Physiology_of_the_Heart%2F17.4B%253A_Electrocardiogram_and_Correlation_of_ECG_Waves_with_Systole \( \newcommand\) • • • • • • • An electrocardiogram, or ECG, is a recording of the heart’s electrical activity as a graph over a period of time. Key Points • An ECG is used to measure the rate and regularity of heartbeats as well as the size and position of the chambers, the presence of damage to the heart, and the effects of drugs or devices used to regulate the heart, such as a pacemaker. • The ECG device detects and amplifies the tiny electrical changes on the skin that are caused when the heart muscle depolarizes during each heartbeat, and then translates the electrical pulses of the heart into a graphic representation. • A typical ECG tracing of the cardiac cycle (heartbeat) consists of a P wave (atrial depolarization ), a QRS complex (ventricular depolarization), and a T wave (ventricular repolarization). An additional wave, the U wave ( Purkinje repolarization), is often visible, but not always. • The ST complex is usually elevated during a myocardial infarction. • Atrial fibrillation occurs when the P wave is missing and represents irregular, rapid, and inefficient atrial contraction, but is generally not fatal on its own. • Ventricular fibrillation oc...

https://med.libretexts.org/@app/auth/3/login?returnto=https%3A%2F%2Fmed.libretexts.org%2FBookshelves%2FAnatomy_and_Physiology%2FAnatomy_and_Physiology_(Boundless)%2F17%253A_Cardiovascular_System%253A_The_Heart%2F17.4%253A_Physiology_of_the_Heart%2F17.4B%253A_Electrocardiogram_and_Correlation_of_ECG_Waves_with_Systole \( \newcommand\) • • • • • • • An electrocardiogram, or ECG, is a recording of the heart’s electrical activity as a graph over a period of time. Key Points • An ECG is used to measure the rate and regularity of heartbeats as well as the size and position of the chambers, the presence of damage to the heart, and the effects of drugs or devices used to regulate the heart, such as a pacemaker. • The ECG device detects and amplifies the tiny electrical changes on the skin that are caused when the heart muscle depolarizes during each heartbeat, and then translates the electrical pulses of the heart into a graphic representation. • A typical ECG tracing of the cardiac cycle (heartbeat) consists of a P wave (atrial depolarization ), a QRS complex (ventricular depolarization), and a T wave (ventricular repolarization). An additional wave, the U wave ( Purkinje repolarization), is often visible, but not always. • The ST complex is usually elevated during a myocardial infarction. • Atrial fibrillation occurs when the P wave is missing and represents irregular, rapid, and inefficient atrial contraction, but is generally not fatal on its own. • Ventricular fibrillation oc...