What leads to look at for axis deviation?
Right Axis Deviation
- Normal variant
- Right bundle branch block
- Right ventricular hypertrophy
- Left posterior fascicular block
- Dextrocardia
- Ventricular rhythms (accelerated idioventricular or ventricular tachycardia)
- Lateral wall myocardial infarction
- Wolff-Parkinson-White syndrome
What is the significance of axis deviation?
What is the significance of left axis deviation? In conclusion, among patients with left bundle branch block, those with left axis deviation have a greater incidence of myocardial dysfunction, more advanced conduction desease and greater cardiovascular mortality than those with a normal axis.
How often is a right axis deviation bad?
RAD on prior ECGs: Chronic right axis deviation is normal in youngsters (less than 21 years of age) and in athletes. It can be a chronic finding in patients with lung disease and RVH or in patients with left posterior hemiblock. The latter is a diagnosis of exclusion.
What condition is often associated with right axis deviation?
Tetralogy of Fallot, transposition of the great arteries, total anomalous pulmonary venous return, ventricular and atrial septal defect may causes cause right-axis deviation 6. Right-axis deviation may also be seen in high degrees of pre-excitation or during a ventricular tachycardia.
What axis deviation tells us?
0:033:22Cardiac Axis Interpretation, Animation. - YouTubeYouTubeStart of suggested clipEnd of suggested clipCardiac axis is the net direction of electrical activity during depolarization. In a healthy heartMoreCardiac axis is the net direction of electrical activity during depolarization. In a healthy heart the net movement is downward and slightly. Left this axis is altered or deviated.
What does left axis deviation mean in ECG?
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°. This is reflected by a QRS complex positive in lead I and negative in leads aVF and II.
What causes axis deviation on ECG?
Most causes can be attributed to one of four main mechanisms. These include right ventricular hypertrophy, reduced muscle mass of left ventricle, altered conduction pathways and change in the position of the heart in the chest.
Is left axis deviation serious?
Left axis deviation (LAD) is the most common “abnormality” in adults, occurring in over 8% of patients. It can be part of the criteria for LVH, but in isolation it has little significance. Marked LAD (45% or more) is calledleft anterior hemiblock orleft anterior fascicular block.
Does left axis deviation mean heart disease?
The results were that the development of left axis deviation in men 40 to 59 yr of age, independent of blood pressure is a significant predictor of ischemic heart disease events that are usually manifest 5 to 10 yr after the onset of this electrocardiographic abnormality.
Can obesity cause left axis deviation?
ECG Abnormalities in Obesity A left shift of the P, QRS and T axes, morphological deviation of the P wave, low QRS amplitude, flattening of T waves (mainly in inferolateral leads) and potentially prolonged QT and QTc intervals are present at a significantly higher rate in obese than in non-obese individuals.
What does abnormal right axis deviation mean?
When right axis deviation is a new finding, it can be due to an exacerbation of lung disease, a pulmonary embolus, or simply a tachycardia. If right axis deviation is a change from previous ECGs, question the patient for symptoms consistent with an exacerbation of lung disease or a pulmonary embolus.
How serious is right axis deviation?
Meanwhile, extreme right axis deviation may be used as a special indicator of poor perfusion in coronary artery as well as left ventricular heart dysfunction. Although there is little electrophysiological explanation, the complications are severe.
What condition is often associated with right axis deviation?
Right axis deviation occurs when the QRS axis is shifted between 90 and 180 degrees. A number of things can result in right axis deviation which include lung disease, right sided heart strain, right bundle branch block, and right ventricular hypertrophy.
What is abnormal ECG?
Abnormal results can signify several issues. These include: Defects or abnormalities in the heart's shape and size: An abnormal ECG can signal that one or more aspects of the heart's walls are larger than another meaning that the heart is working harder than normal to pump blood.
What is pulmonary disease pattern on ECG?
ECG demonstrates many of the features of chronic pulmonary disease: Rightward QRS axis (+90 degrees) Peaked P waves in the inferior leads > 2.5 mm (P pulmonale) with a rightward P-wave axis (inverted in aVL) Clockwise rotation of the heart with a delayed R/S transition point (transitional lead = V5)
What is borderline axis deviation?
For example, if the isoelectric limb lead is lead II, which has a positive end directed at +60 degrees, then the electrical axis is directed approximately 90 degrees from +60 degrees in either direction. Therefore, the axis can lie at around +150° (right axis deviation) or -30 degrees (borderline left axis deviation).
What are the symptoms of left axis deviation?
For example, if left ventricular hypertrophy (LVH) is the cause of LAD, symptoms can include shortness of breath, fatigue, chest pain (especially with exercise), heart palpitations, dizziness, or fainting. If a conduction defect such as left bundle branch block is ...
What is the cardiac axis?
Cardiac axis in electrocardiography represents the sum of depolarization vectors generated by individual cardiac myocytes. To interpret the cardiac axis, one has to determine the relationship between the QRS axis and limb leads of the ECG. Usually, left ventricles makes up most of the heart muscles, so a normal cardiac axis is directed downward ...
What is the axis of the left ventricle?
In a normal axis, QRS is between -30° and +90°. In contrast to that, left axis deviation (LAD) is defined as QRS axis between −30° and −90°, and right axis deviation is defined as QRS axis greater than +90°, ...
What causes left axis deviation?
Left-axis deviation that occur in hyperkalemia are due to a intra-venticular conduction delay, which causes a progressive widening of the QRS complex. P wave also increases in duration and decreases in amplitude and, furthermore, other disorders may appear, such as AV blocks , sick sinus syndromes or junctional rhythms.
Which direction does the QRS axis shift with age?
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.
Which axis does the QRS vector shift to?
Most obese patients without clinical heart disease have normal EKGs, with the mean QRS vector shifting to the left with increasing obesity 3.
What causes right axis deviation 6?
Abnormalities of axis are rarely specific in the diagnosis of congenital heart diseases. Tetralogy of Fallot, transposition of the great arteries, total anomalous pulmonary venous return, ventricular and atrial septal defect may causes cause right-axis deviation 6.
Is lead AVR upside down?
Lead aVR is actually lead aVL and vice versa. When the left and right arm leads are reversed, the EKG reveals the following changes: Lead I is upside down because the polarity of the lead is reversed. Lead II is actually lead III and vice versa. Lead aVR is actually lead aVL and vice versa.
What is the cardiac axis?
Cardiac axis represents the sum of depolarisation vectors generated by individual cardiac myocytes. Clinically is is reflected by the ventricular axis, and interpretation relies on determining the relationship between the QRS axis and limb leads of the ECG (below diagram)
What is the normal axis of the left ventricle?
Since the left ventricle makes up most of the heart muscle under normal circumstances, normal cardiac axis is directed downward and slightly to the left: Normal Axis = QRS axis between -30° and +90°. Abnormal axis deviation, indicating underlying pathology, is demonstrated by:
What is the cardiac axis?
What is cardiac axis? The electrical activity of the heart starts at the sinoatrial node then spreads to the atrioventricular (AV) node. It then spreads down the bundle of His and then Purkinje fibres to cause ventricular contraction.
What is the normal axis of the heart?
Normal cardiac axis. In healthy individuals, you would expect the axis to lie between -30° and +90º. The overall direction of electrical activity is towards leads I, II and III (the yellow arrow below).
What gives us an idea of the overall direction of electrical activity?
Whenever the direction of electrical activity is away from a lead you get a negative deflection in that lead. Cardiac axis gives us an idea of the overall direction of electrical activity. Cardiac conduction. Cardiac axis.
Is RAD a normal finding?
RAD is commonly associated with conditions such as pulmonary hypertension, as they cause right ventricular hypertrophy. RAD can, however, be a normal finding in very tall individuals. Right axis deviation 1.
Overview
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°. This is reflected by a QRS complex positive in lead I and negative in leads aVF and II.
There are several potential causes of LAD. Some of the causes include norma…
Defining left axis deviation
Cardiac axis in electrocardiography represents the sum of depolarization vectors generated by individual cardiac myocytes. To interpret the cardiac axis, one has to determine the relationship between the QRS axis and limb leads of the ECG. Usually, left ventricles makes up most of the heart muscles, so a normal cardiac axis is directed downward and slightly to the left. In a normal axis, QRS is between -30° and +90°. In contrast to that, left axis deviation (LAD) is defined as QR…
Determining left axis deviation
Determining the electrical axis can provide insight into underlying disease states and help steer the differential diagnosis. There are several methods to determining the ECG axis. The easiest method is the quadrant method, where one looks at lead I and lead aVF. First, examine the QRS complex in both leads I and avF and determine if the QRS complex is positive (height of R wave > S wave), equiphasic (R wave = S wave), or negative (R wave < S wave). If lead I is positive and le…
Causes
There are several potential causes of LAD. These include normal variation, left ventricular hypertrophy, conduction defects, inferior wall myocardial infarction, preexcitation syndrome, ventricular ectopic rhythms, congenital heart disease, hyperkalemia, emphysema, mechanical shift and pacemaker-generated paced rhythm. Normal variation causing LAD is an age-related physiologic change. Conduction defects such as left bundle branch block or left anterior fascicula…
Signs and symptoms
Left axis deviation symptoms depend on the underlying cause. For example, if left ventricular hypertrophy is the cause of LAD, symptoms can include shortness of breath, fatigue, chest pain (especially with exercise), palpitations, dizziness, or fainting. If a conduction defect such as left bundle branch block is the cause of LAD, there may not be any symptoms unless the conduction defect is caused by heart failure, in which case there can be symptoms of heart failure such as sh…
Treatment
Left axis deviation per se does not require treatment, however the underlying cause can be treated. If left ventricular hypertrophy is the cause of LAD, treatment depends on the underlying cause of the hypertrophy. If high blood pressure is the cause of LVH, then treatment is targeted at lowering blood pressure and preventing further enlargement of the left ventricle by using medications such as angiotensin-converting enzyme inhibitors (ACE inhibitors), angiotensin recep…
See also
• Right axis deviation