What is Crochetage?

Learning points. A notch near the apex of the R wave in inferior limb leads of ostium secundum atrial septal defects has been called ‘crochetage’ because the notch resembles the work of a crochet needle.

What is ostium primum defect?

Ostium primum defect is a congenital malformation involving atrial septum contiguous with atrioventricular valve annulus; it is accompanied by abnormalities in the development of the endocardial cushions, often resulting in associated atrioventricular valves malformations.

What is ostium secundum atrial septal defect?

An ostium secundum atrial septal defect is a type of congenital heart defect called an atrial septal defect (ASD). An ASD is a hole in the wall (septum) between the two upper chambers of the heart (the atria). ASDs can be classified by location. An ostium secundum ASD is a hole in the center of the atrial septum.

Why is atrial septal defect a systolic murmur?

This is caused by blood flow from the left atrium into the right atrium through the atrial septal defect. There is further turbulent flow into the pulmonary artery causing the systolic murmur.

What is the QRS width of an ECG?

The QRS width is 94 milliseconds. Inferior leads show notched R waves: Crochetage sign. ECG 1b. The compact ECG above belongs to the same patient. It was recorded 30 days after surgical closure of his large secundum ASD. Right ventricular volume overload is not present anymore. The QRS width has decreased to 84 milliseconds.

What does the crochetage sign on an EKG mean?

ECHOcardiography showed a dilated right ventricle and a dilated right atrium. The QRS width is 94 milliseconds. Inferior leads show notched R waves: Crochetage sign. ECG 1b. The compact ECG above belongs to the same patient. It was recorded 30 days after surgical closure of his large secundum ASD.

Is the QRS complex a positive or negative wave?

If the first wave is negative then it is referred to as Q-wave. If the first wave is not negative, then the QRS complex does not possess a Q-wave, regardless of the appearance of the QRS complex. All positive waves are referred to as R-waves.

What does the prolongation of the QRS complex mean?

Prolongation of QRS duration implies that ventricular depolarization is slower than normal. The QRS duration is generally <0,10 seconds but must be <0,12 seconds. If QRS duration is ≥ 0,12 seconds (120 milliseconds) then the QRS complex is abnormally wide (broad). This is very common and a significant finding.