Quiz #27 Answer: EKG with ST segment elevation

6 yr old boy, s/p Repair of subaortic membrane. Two EKGs with time are given – both recorded on the day of surgery. One is immediately after coming from OR and the other ~10 hrs later. Second EKG was performed due to EKG change in monitor. Hemodynamically stable. Patient is sleeping without any complaints.

1)      Describe the most significant change.

2)      What is the possible reason for the change?

Answers:

1)      St elevation in every lead except aVL and V1.

2)      Possible pericarditis – post-op.

Other possibilities:

1) Acute Myocardial Infarction

2) Hyperkalemia

3) Hypothermia

(All are discussed below in detail).

Patient Follow-up: No further investigations were done. Discharged home in 48 hrs. without any problems. Treated with Ibuprofen just like many other postop. cardiac patients. Followed by outside cardiologist.

Pericarditis: Characteristics of changes in Pericarditis: ST segment with concavity upwards and presence of this change in multiple leads favors diagnosis of pericarditis.

Ischemia or infarction changes will occur in specific areas that are affected (i.e. inferior leads, anterior leads, lateral leads, etc.) with reciprocal changes in “opposite” leads. Pericarditis typically involves ST elevation “all” leads and may not follow specific lead groups.

(Principles of Clinical Electrocardiography (11^th ed) by Mervin J. Goldman. Lange Medical Publications 1982, page 285).

AMI: Figure below shows acute EKG changes in inferior wall infarction in column B (Column A is normal EKG for comparison. Note the shape of ST segment (covexity upwards in II, III & aVF) and reciprocal changes in I, aVL, V1-V6).

(From Principles of Clinical Electrocardiography (11^th ed) by Mervin J. Goldman. Lange Medical Publications 1982, page 170)

Hyperkalemia: Hyperkalemia can present this way, but usually is associated with Tall peak T waves as well. Patient’s K in ABGs were normal. Below is an EKG strip from a newborn with Sr. K 9.1. The ST elevation and Tall T waves in hyperkalemia resemble AMI changes. But, these changes (at this Sr. K levels) will be interspersed with other EKG changes of QRS complex and arrhythmias as in this patient. (This baby was diagnosed with congenital adrenal hyperplasia later. Cardiology was consulted for bradycardia!)

Hypothermia: Occurs with characteristic appearance of Osborne waves (arrows). And, also occur with prolongation of QRS duration and QTc. Therefore, it is reasonable to do a 12-l2-lead EKG before instituting hypothermia protocol as an elective procedure (not possible when initiated during CPR).

(Image from internet)

Quiz 26: Clinical Sign

Questions:

1) Sulcus indicated by the dashed line in the chest of this infant is named after a physician. What name is it.

2)      Provide differential diagnoses for this clinical sign (including at least one relevant to cardiology).

Answers:

1) Harrison sulcus

2)      Diffierential diagnosis: (i) Rickets, (ii) Asthma and (iii) Congenital heart disease with significant L-R shunt. 

Discussion:
The line of indrawing approximately corresponds to insertion of diaphragm and is thought to be caused by repeated, forceful diaphragmatic pull during infancy when the bony cage is relatively soft. This occurs with any condition associated with chest retractions (Asthma & L-R shunt lesions in the heart). In rickets, normal pull of the diaphragm on the softer the bony cage (softer, due to rickets) is considered the reason.

Unnati sent this article on Harrison’s groove: Naish J & Wallis HRE. The significance of Harrison’s grooves. Br Med J 1948;1:541-44. This article has a discussion on mechanism of causation of this groove (or sulcus). It questions the theory of diaphragmatic pull in the early part. But, later part of the discussion provides evidence from work of Herlitz (1945) that supports this theory.

Quiz #25: Echo - Identify the vessel (again!)

Quiz #25:

Going with the same theme in Quiz #24.

Subcostal sagittal (bicaval) view in a newborn with severe cyanosis.

(Some labels are given because the picture is somewhat unclear. Clue: A vertical vessel flowing downwards, behind the IVC).

Question:

1)      Name the vessel shown by arrow.

2)      Provide a possible diagnosis. (I won’t be upset if you gave a second possible diagnosis as well!)

Answers:

1)      Vertical vein with flow from above downwards.

2)      Infradiaphragmatic type TAPVR

a.       Second possibility: SVC obstruction with decompression via Azygos vein (flowing downwards),

b.      Other possibilities (but, not typical) given by fellows who replied were

                                                               i.      Veno-venous collateral – I guess this may occur anywhere when there is a “set up” for it.

                                                             ii.      Scimitar syndrome – But, I think, the scimitar vein does not cross diaphragm as far as this image shows.

Quiz #24: Echo - Identify the vessel - Answer

Subcostal saggital view from a newborn with multiple congenital heart defects.

Questions:

1)      Name the vessel shown by the arrow.

2)      What is the possible reason for dilation of this vessel?

Answers:

1) Azygos vein

2) Dilated azygos vein, secondary to interrupted IVC.