Challenging Cases in Bedside !!!
According to ACC/AHA classification of Chest pain .
1) Be careful of the Chest pain definition Cardiologically : typical chest pain is :
i) substernal chest discomfort with characteristic quality and duration .
ii) Provoked by exertion or emotional stress
iii) relived by Nitroglycerine or GTN
2) Atypical Angina ( probable)
i) Meets two of above criteria
3) Non-cardiac chest pain
i) Meets one or none of above Criteria for typical angina
Conclusion : Atypical chest pain and Non cardiac either can be Chest pain due to that it’s better to call it Chest DISCOMFORT . so then , our patient has (chest discomfort ) .
So what is definition of “Prior ischemic “ chest pain , or “Low risk “ Chest pain
1) Prior ischemic chest pain ; is defined as a past knew diagnosis of MI , or angina , previously prescribed GTN or a clear history of effort related angina .
2) low risk chest pain ; is defined as pain not radiating OR increased with deep breath OR increased with palpation .
Conclusion ; this patient has both lack of prior ischemic chest pain and presence of Low risk chest pain .
OUR PATIENT IS CONFIRMED WITH CHEST PAIN .
Next step is coming to ECG .
in ECG there is only one well known Criteria of “Brugada “ to differentiate new and old STEMI with LBBB. What is that :
1- ST – segment elevation > 1 mm concordance with QRS ( 5 scores)
2- St-segment depression ≥1mm in lead v1,v2,or v3 . ( 2 scores)
3- ST-segment elevation ≥ 5mm disconcordant with QRS ( 2scores)
note: points score for each criterion met are added . total point score of 3 yields ≥90% speficity and an 88% positive predictive value .
conclusion ; so our ECG shows LBBB with STEMI in Anteroseptal wall even in V3-V4 more than , 5mm. our criteria is third one . takes two scores less than those specificity and PPV. But is still conforming . be careful to measure ST-segment elevation 60 t0 80 milisecond beyond J point , J point elevation is not favor method for measuring STEMI .
so , what is the new criteria for differentiating new and old LBBB , in Heart rhythm Journal by Heart rhythm society confirmed that there is new criteria that is most specific and sensitive for old and new LBBB +MI detection is T wave voltage criteria, to cut it short , take the first ECG see the amplitude of T wave how much is elevated than the 2 hours , 6 hours and 24 hours ECG . if this amplitude is decreased in later ECGs this is Fresh LBBB + MI otherwise not .
From other sides , there is a lots of event can give ST elevation especially DCM and aneurysm if ST segment after an MI continue to be elevated beyond two weeks . the patient have aneurysm . !!!
Conclusion : According to ECG our patient is in class third Brugada and the later ECG have shown decreased the T wave amplitude notoriously . so , then , our Patient has Fresh MI and Fresh LBBB.
OUR PATIENT IS FRESH MI + RECENT ONSET LBBB
Third never forget Echocardiography in a such patients; in ECHO patients shows ischemic DCM pattern with severely systolic dysfunction EF was about 25%. LV and LA was dilated. for ischemic DCM there is no need to have four chambers dilated. With, akinetic Anteroseptal wall motion abnormality. so , simple transthoracic echocardiography can differentiate between Ischemic DCM and other Dilated cardiomyopathies . we must perform , dobutamic stress echocardiography for sure diagnosis of this differentiation points . we didn’t because still we are scared of Infarction ….. so , then , can a new Infarction give DCM in one or two or three days ??? No , Cardiomyopathy after Infarction is starting beyond two weeks to months on .
Result : Previously for confirming MI there was who criteria that have three component of 1) chest pain , 2) Positive troponins 3) ECG changes ,that if a patient having 2 out of these threes is accepted as a Infarction . ECG changes. But , recently the ESC/ACC/AHA/WHF/WHO, added two others components for this ; 4) imaging findings such as Echocardiography and 5) pathological findings . this criteria is called revised criteria .
so . we have , ECG criteria positive, clinical criteria positive , troponins is not trusted early in MI onset , it needs 3-6 hours from occlusion toward delectability that we gave it early in the first and be careful of false positivity of low range troponins and false negativity of Troponin T also . thus , it needs , serial monitoring of troponins . Pathological investigations are not possible in early hours in majority of hospitals. Echocardiography confirmed ischemic DCM findings of Chronic Cardiomyopathy ( remodeling ) , that one question must be asked that is there any phenomenon by the name of Acute remodeling ? the answer is obviously “yes” , but , those are aneurysm and acute complications of MI that our patient was in Ischemic DCM that is a chronic process and suggesting the Old Infarction of this patients complicated to DCM and reinfarction that this patient is still in compensated Heart failure. However the reinfarction diagnosis is very difficult in first hours of Hospital staying but the ECG Criteria plus clinic of patient OR, DCM by itself became a window for detecting Infarct extension. Once attention must be paid that silent ischemia represents an underappreciated manifestation of CAD. These patients are considered to have an a ineffective “angina warning system” . this patient had Type I silent ischemia that is defined as asymptomatic ischemia without history of infarction .
between 20-40% of patients with chronic angina symptoms have silent ischemia . In these patients about 75% ischemic episodes are silent and only 25% are symptomatic, even during heavy exercise . finally I want to point out about new aspects of determining the LV ejection fraction by ECG. There is two criteria the one is the QRS scoring system that can measure the Ejection fraction, but it is a bit difficult . the most easy method is LBBB with prolong QRS duration that is very simple and bedside , how much the patient’s ECG strip have wider QRS complex with presence of LBBB the Ejection fraction is lower . As in this patient ECG strip there is unusually Wide QRS complex > 160 ms. The reason is the “dyssynchrony” that this patient had AV and Interventricular dyssynchrony .
Writer : Dr.Nabil Paktin , MD,FACC