Left axis deviation ecg

Related articles: Extreme axis deviation, also known as extreme right axis deviation, northwest axis or “no-man's land” axis, is a rare electrocardiographic finding, and it represents an extreme right- or left-axis deviation 1. In adults, the normal QRS axis is considered to be within -30° and 90°. Extrem axis deviation is when the QRS axis is between -90° and -180º. The situations in which extreme axis deviation may be seen are as follows: Right Arm and Left Leg Leads Reversal Reversal of the right arm and left leg leads is the most common cause of extreme axis deviation. When the right arm and left leg leads are reversed, the EKG reveals the following changes 2: • Lead I is actually upside-down lead III. • Lead II becomes upside down. • Lead III is actually upside-down lead I. • Leads aVR and aVF are reversed. • Lead aVL is unchanged. When all the deflections, including the Pwave, are negative in lead aVF, a right arm and left leg leads reversal should be suspected 2. Ventricular Rhythms Related article: Ectopic ventricular rhythms ( Ventricular Tachycardias Related article: Ventricular tachycardias are a group of arrhythmias characterized by the presence of three or more consecutive ventricular beats with a high heart rate. Ventricular tachycardias with right superior axis (extreme axis deviation) usually arise from the apex or septal regions of the left ventricle. Ventricular tachycardias arising from the apex have More information: Accelerated Idioventricular Rhythm A...

Related articles: In adults, the normal QRS axis is considered to be within -30° and 90°. Left-axis deviation is when the QRS axis is between -30° and -90º. Moderate left-axis deviation is between -30° and -45°. Marked left-axis deviation is from -45° to -90° and is often associated with 1. The situations in which left-axis deviation may be seen are as follows: Causes of Left Axis Deviation Note that the first three account for almost 90% of EKG tracings with left-axis deviation. • Normal variation: elderly or obese patients. • • • • Inferior wall myocardial infarction. • Ventricular ectopic rhythms (e.g., • Congenital heart disease: primum atrial septal defect, atrioventricular canal. • • Emphysema. • Mechanical shift, such as with expiration or raised diaphragm: • 2. Normal variation The mean QRS axis tends to shift leftward with increasing age. The leftward shift of the QRS axis with aging is particularly prevalent in overweight subjects and is more pronounced in older obese men than in older obese women 3. There is an association between the QRS axis and body weight, overweight individuals tend to have a more leftward axis. Most obese patients without clinical heart disease have normal EKGs, with the mean QRS vector shifting to the left with increasing obesity 3. Left Ventricular Hypertrophy Related article: In patients with 2. The most frequent findings of LVH on the EKG are tall R waves in left precordial leads (V5-V6) and deep S waves in right precordial leads (V1-V...

Atrial septal defect (ASD), also known as interatrial communication, is the fifth congenital heart disease in order of frequency. The International Society for Nomenclature of Paediatric and Congenital Heart Disease (ISNPCHD) has defined an interatrial communication as a congenital cardiac malformation in which there is a hole or pathway between the atrial chambers 1. Atrial septal defect is classified according to the area of the septum in which it is located. In general, its anatomical forms are: • Ostium secundum: they are the most common type of ASD, constituting 80% of the cases. It is located in the area of the fossa ovalis. • Sinus venosus: they comprise 5% of ASD. They are locatedin the superior or inferior region of the interauricular septum, near the superior or inferior vena cava respectively. • Ostium primum: they are the second most frequent ASD, up to 15%. It is located near the crux of the heart, and is usually associated with other defects such as mitral cleft, presence of common atrioventricular valve, or inlet ventricular septal defect. Ostium Secundum and Sinus Venosus Normally, these cardiopathies do not show signs of clinical relevance until the child is over 3or 4years old. The electrocardiogram presents the same findings in the ostium secundum and venous sinus forms. The left to right shunt that occurs at the atrial level causes volume overload of the right atrium and the right ventricle, as well as increased pulmonary flow; this is observed with Ost...

Atrial septal defect (ASD), also known as interatrial communication, is the fifth congenital heart disease in order of frequency. The International Society for Nomenclature of Paediatric and Congenital Heart Disease (ISNPCHD) has defined an interatrial communication as a congenital cardiac malformation in which there is a hole or pathway between the atrial chambers 1. Atrial septal defect is classified according to the area of the septum in which it is located. In general, its anatomical forms are: • Ostium secundum: they are the most common type of ASD, constituting 80% of the cases. It is located in the area of the fossa ovalis. • Sinus venosus: they comprise 5% of ASD. They are locatedin the superior or inferior region of the interauricular septum, near the superior or inferior vena cava respectively. • Ostium primum: they are the second most frequent ASD, up to 15%. It is located near the crux of the heart, and is usually associated with other defects such as mitral cleft, presence of common atrioventricular valve, or inlet ventricular septal defect. Ostium Secundum and Sinus Venosus Normally, these cardiopathies do not show signs of clinical relevance until the child is over 3or 4years old. The electrocardiogram presents the same findings in the ostium secundum and venous sinus forms. The left to right shunt that occurs at the atrial level causes volume overload of the right atrium and the right ventricle, as well as increased pulmonary flow; this is observed with Ost...

Related articles: Extreme axis deviation, also known as extreme right axis deviation, northwest axis or “no-man's land” axis, is a rare electrocardiographic finding, and it represents an extreme right- or left-axis deviation 1. In adults, the normal QRS axis is considered to be within -30° and 90°. Extrem axis deviation is when the QRS axis is between -90° and -180º. The situations in which extreme axis deviation may be seen are as follows: Right Arm and Left Leg Leads Reversal Reversal of the right arm and left leg leads is the most common cause of extreme axis deviation. When the right arm and left leg leads are reversed, the EKG reveals the following changes 2: • Lead I is actually upside-down lead III. • Lead II becomes upside down. • Lead III is actually upside-down lead I. • Leads aVR and aVF are reversed. • Lead aVL is unchanged. When all the deflections, including the Pwave, are negative in lead aVF, a right arm and left leg leads reversal should be suspected 2. Ventricular Rhythms Related article: Ectopic ventricular rhythms ( Ventricular Tachycardias Related article: Ventricular tachycardias are a group of arrhythmias characterized by the presence of three or more consecutive ventricular beats with a high heart rate. Ventricular tachycardias with right superior axis (extreme axis deviation) usually arise from the apex or septal regions of the left ventricle. Ventricular tachycardias arising from the apex have More information: Accelerated Idioventricular Rhythm A...

Related articles: In adults, the normal QRS axis is considered to be within -30° and 90°. Left-axis deviation is when the QRS axis is between -30° and -90º. Moderate left-axis deviation is between -30° and -45°. Marked left-axis deviation is from -45° to -90° and is often associated with 1. The situations in which left-axis deviation may be seen are as follows: Causes of Left Axis Deviation Note that the first three account for almost 90% of EKG tracings with left-axis deviation. • Normal variation: elderly or obese patients. • • • • Inferior wall myocardial infarction. • Ventricular ectopic rhythms (e.g., • Congenital heart disease: primum atrial septal defect, atrioventricular canal. • • Emphysema. • Mechanical shift, such as with expiration or raised diaphragm: • 2. Normal variation The mean QRS axis tends to shift leftward with increasing age. The leftward shift of the QRS axis with aging is particularly prevalent in overweight subjects and is more pronounced in older obese men than in older obese women 3. There is an association between the QRS axis and body weight, overweight individuals tend to have a more leftward axis. Most obese patients without clinical heart disease have normal EKGs, with the mean QRS vector shifting to the left with increasing obesity 3. Left Ventricular Hypertrophy Related article: In patients with 2. The most frequent findings of LVH on the EKG are tall R waves in left precordial leads (V5-V6) and deep S waves in right precordial leads (V1-V...