“Andromeda”, oil on canvas, 1869, Gusatve Dore, private collection.
Andromeda was the beautiful daughter of Cepheus, the king of Ethiopia and his wife Cassiopia. She was more beautiful than any other mortal; in fact her beauty rivaled even that of the goddesses. Her mother Cassiopia would continually boast to anyone who would listen that her daughter was even more beautiful than the semi goddesses, the Nereids, nymphs of the sea who were renowned as the most beautiful of all the immortals. Soon news of Cassiopeia’s boasting reached the ears of the Nereids, who then complained bitterly to Poseidon, the supreme god of the seas. Outraged at such arrogance shown to the gods by a mere mortal Poseidon decided to let loose the fearful sea monster of the deep, the Kraken in order that it would attack and destroy the Empire of Cepheus. The Kraken brought terror and destruction to the land and the people were powerless against it. In desperation Cepheus consulted the most powerful oracle of his lands, who informed him that the only way to avert the total annihilation of his people was to offer up his daughter Andromeda in sacrifice to the Kraken, even though she was totally innocent of her mother’s boasting. This was only way to calm the wrath of Poseidon. After intense emotional turmoil Cepheus decided that this must be done for the good of his people. On a dark stormy night, Andromeda was taken to the treacherous sea cliffs were the monster lurked and chained naked to the rocks and left to be devoured by the creature.All seamed lost to the pitiful Andromeda, but just as she was about to be devoured by the Kraken, she was suddenly noticed by the eagle eye of Perseus upon his winged horse Pegasus, who was flying far overhead carrying with him the monstrous head of the Medusa, whom he just recently slain. He immediately noticed not only the danger Andromeda was in, but also how beautiful she was even from such a distance. He fell instantly in love and decided that he must rescue her even if it meant combat to the death with the fearful Kraken. After a heroic struggle he was able to overcome the monster with the aid of the head of the Medusa that had the power to turn objects to stone, and a magical sword that was given to him by the god, Hermes and so rescued Andromeda from her certain fate. Andromeda fell in love with Perseus and they married and eventually became the king and queen of the city of Tiryns in Argos.
When Perseus and Andromeda died after long and prosperous lives, the goddess Athena, much taken by their story, had them placed forever among the stars of the firmament. Today they can be seen together in the northern skys, the constellation of Andromeda with her arms up stretched is if chained to the rocks and nearby, the constellations of Perseus and Pegasus, his winged horse. Like the hero Perseus, we must remain ever eagle-eyed for the signs of imminent disaster in our patients in the form of the Wellen’s syndrome ECG. Unfortunately not many of these patients will induce us to fall instantly in love, yet we can at least take comfort in the thought that, like the sword and head of the Medusa in the armamentarium of Perseus, we too are well equipped to take on this imminent disaster with our own weaponry in the form of angiography and interventional angioplasty. It is to be hoped that our heroics will also result in long and prosperous lives for our patients though it is probably too much to expect that Athena will immortalize us among the stars of the firmament for this. WELLENS SYNDROME
Wellens syndrome is a group of dynamic ECG signs that occur during the pain free period in a patient with a recent history of chest pain / discomfort.
The ECG signs suggest the presence of a critical stenosis in the proximal left anterior descending (LAD) coronary artery. These patients are at risk of extensive and “imminent” (mean period 8.5 days according to some studies) anterior myocardial infarction.1
In view of the large area of ventricle at risk, they require urgent coronary angiography to confirm the lesion and need early intervention such as bypass grafting or percutaneous coronary intervention, (PCI).
See also Guidelines on Left Main Coronary Artery Critical Stenosis. Pathophysiology
● Typical ECG features show T wave inversion with a biphasic pattern. This is best seen in leads V2 and V3. This is the “Wellens” sign and actually represents a reperfusion, (whilst the patient is pain free) of the myocardium.
● Whilst the biphasic T wave changes on their own can be relatively non-specific, it is the progression todeepandsymmetricalT wave inversion, during pain free periods, which virtually makes the diagnosis.
● During pain, these ECG changes can be replaced by positive T waves, with the ST segments showing elevation or depression, (as the coronary vessel critically narrows or occludes) - a “pseudo normalization”.
● With progression to complete occlusion and infarction, the typical pattern of ST segment elevation (STEMI) will occur.
12 lead ECG showing the typical biphasic T wave changes of Wellens syndrome in V2 and V3 as well as deep symmetrical T wave inversion seen in V4 (This patient had a 90% stenosis of the proximal LAD). ● ECG changes usually resolve once the stenosis is corrected.
● Note that troponin levels may or may not be elevated and so a normal troponin level does not rule out the presence of a critical stenosis, that needs urgent management.
● Early benign repolarization changes commonly lead to abnormal appearing ST-T-wave complexes in the precordial leads.
They usually occur in young adults and are characterized by an elevated initial portion of the ST segment (J-point elevation), but not a biphasic T wave.
● The differential diagnosis of “non-specific” ST changes in the early precordial leads is extensive and includes acute ischemia, “old” changes, pericarditis, myocarditis, bundle branch block, digitalis effects and non-cardiac conditions such as dissecting aneurysm, hypokalemia and pulmonary embolism.
Dynamic ECG changes of Wellen’s syndrome:
The above shows the progression of Wellen’s syndrome from admission in the Emergency Department to 30 hours later, before angiography, (which showed a critical stenosis of the LAD). Note the significant changes in the T waves in V2 and V3 in particular. These changes are not detected in V1.1 Management For patients suspected of having this syndrome indicating a critical proximal stenosis of the LAD:
1. Control any recurrent episodes of pain with usual regimes of morphine and nitrates as required.
2. Give aspirin 150 mg.
3. Clopidogrel is probably best avoided in the first instance, in case urgent CAGS is required.
4. Commence anticoagulation therapy;
● IV heparin is preferred to clexane, in the first instance, in view of the need for urgent angiography.
● Clexane may be given after discussion with the cardiologist concerning the timing of angiography.
Disposition All patients suspected of having a critical stenosis of the LAD should
1. Be admitted for continuous 12 lead ECG monitoring.
● Note that monitoring on lead 11 or V1 only is not sufficient, as the dynamic ECG changes of the syndrome will be missed.
2. Be referred urgently to the Interventionist Cardiologist on call, with a view to early/urgent coronary angiography. ● Note that stress testing should be avoided as this may precipitate an MI 2
References 1. Conover M. B: Wellen's Syndrome in Understanding Electrocardiography, Mosby, 8th ed 2003.
2. Tandy TK, Bottomy DP, Lewis JG. Wellens Syndrome. Ann Emerg Med 1999; 33: 347-51.
3. De Zwaan C, Bar FW, Wellens HJ. Characteristic electrocardiographic pattern indicating a critical stenosis high in left anterior descending coronary artery in patients admitted because of impending myocardial infarction. Am Heart J 1982; 103(4 pt 2): 730-6.
4. Rhinehardt J, et al: Electrocardiographic Manifestations of Wellens’ Syndrome. American Journal of Emergency Medicine, vol 20 no.7, November 2002, p. 638- 643.
Dr J. Hayes