Case Presentations

Case 1

Contributed by :

Mahapatra G.N.
Patted S.V., Dixit M.D.,
Department of Nuclear Medicine, Cardiology and Cardiothoracic surgery, KLES Hospital, Belgaum, Karnataka State.

A 66 year old medical professional presented to the cardiac outpatient department with history of IHD. He is obese with type-II diabetes mellitus in controlled state and he is hypertensive which is controlled with medications. He underwent treadmill test which was positive for IHD with ST depression and T inversion in II, III avf leads. Further the patient was referred to the Nuclear Cardiology department for obtaining the status of old MI with any new areas of fresh reversible ischaemia before sending for cardiac catheterization.

Question:
Does myocardial perfusion scintigraphy helps as an important diagnostic tool in patient having old MI prior to cardiac catheterization ?

Answer :
Tc99m gated Stress and Rest Tetrofosmin (Myoview) myocardial perfusion scinitigraphy was performed under SPECT Diacam Gamma Camera interfaced with Icon digital computer. Moderate level of exercise was given in a treadmill monitoring the pulse rate, blood pressure and ECG changes. Patient could achieve a heart rate of 151/min with a product of 31,500. ST-T changes in the form of ST depression was evident in I, II,avf, V4, V5, V6 with occasional ventricular ectopic beats. Tc99m Tetrofosmin of 12mCi was injected at the peak of the exercise. 30 min following the cessation of exercise gated stress images were acquired. Four hour after 20 mCi of Tc99m Tetrofosmin was administered in resting condition and 30 min after resting images were acquired.

Question:
Does this Medical professional needs cardiac catheterization ?

Interpretation:
Gated stress and rest Tc99m labelled Tetrofosmin myocardial perfusion study showing moderately low LVGEF at rest (34%) with almost akinetic inferior and posterolateral segments without any evidence of systolic wall thickening with failure to rise in LVGEF at stress (33%) with persistence of the above mentioned wall motion abnormalities. Multiple moderate areas of fixed perfusion defects involving inferior, posterolateral segments of the myocardium with a small area of reversible ischaemia seen in anterior segment territory.

This study suggests that the affected segments following history of old MI has converted to a state of scarred myocardium giving an important information to the cardiologist and cardiac surgeon that cardiac catheterization is not indicated as dead myocardium following old MI would not recovery back to its normally functioning pattern following revascularisation.

Conclusion:
Thus myocardial perfusion scintigraphy should always be a frontline mandatory investigatory tool in all patient having a history of old MI prior to cardiac catheterisation.

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Case 2

Contributed by

* Mahapatra G.N.
** Mehta Priya
*** Pathak Lekha
**** Dalal J.J

* Dept of Nuclear medicine , Mandakini Nuclear Imaging Centre, Chembur, Mumbai.
Department if Nuclear Medicine KLES Hospital & Research Centre, Belgaum, Karnataka

** Dept of Nuclear medicine, Gujarat Cancer Research Centre, Ahemdabad.

*** Consultant Cardiologist, Nanavati Hospital Mumbai.

****Consultant Cardiologist , Hinduja Hospital Mumbai.


A 45 year man presented to the cardiac clinic for routine cardiac check up. There is a strong family history of ischaemic heart disease. He is non diabetic, obese & not having dyslipidemia. There is no past history of known M.I. A coronary angiography was performed which reveals a lesion of 70% at the origin of DI ( diagonal) & 60-70% in L.A.D. L.C.X & R.C.A are normal with E.F of 60% . Since there is a borderline lesion in L.A.D territory , stress thallium myocardial perfusion scan was advocated for measuring the hemodynamic significance of observed stenosis.

Question :

Does this patient needs coronary intervention ?

Answer :

Stress thallium myocardial scintigraphy was performed under SPECT gamma camera interfaced with digital computer. Bicycle ergometer exercise was given to the patient in a graded manner (40 watt, 50 watt) & the patient achieve a target heart rate of 85% of the resting heart rate i.e 162/min. IV administration was given at this peak of exercise. Immediate stress & resting thallium images after 4 hours were obtained.

Various thallium slices at the stress shows uniform stress perfusion pattern involving antero-septal, antero-lateral, postero-lateral & infero-apical segment of myocardium suggesting no significant areas of perfusion defects.

Conclusion :

Coronary intervention has been avoided and the patient has been followed up for the past 16 months with mild coronary vasodilators & regular exercise. The importance of myocardial perfusion scan in borderline lesion is very vital to decide whether to go for coronary intervention or not.

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Case 3

Contributed by

Mahapatra G. N.
Shetty Jayram
Yadwad Adarsh
Halkatti Prabhu
Dixit MD
Dept of Nuclear Medicine Cardiology & Cardiothoracic Surgery
Kles Hospital, Belgaum, Karnataka

A 50 year old male presented to the cardiac out patient department with mild shortness of breath & no significant pain in the precordium with history of old MI for which he was admitted to Intensive Care Unit-6 months back. There is a strong family history of ischaemic heart disease . Electrocardiogram reveals evidence of old myocardial infarction involving anteroseptal and inferior wall leads. Subsequently coronary angiography was performed 8-10wks after patient stabilized in ICU . This reveals a complete 100% occlusion of LAD territory & 80-90% lesion in LCX territory with EF of 30% RCA territory was free of disease.

Question:
 Does this patient need myocardial perfusion study before coronary intervention ?
 

Answer :

Tc-99m Tetrofosmin (Myoview) myocardial perfusion scintigraphy was performed under SPECT Diacam Gamma camera interfaced with digital computer. Moderate level exercise was given on a treadmill monitoring the pulse rate, blood pressure & ECG changes. Patient could achieve a heart rate of 140/min without any new ECG changes on other territories following which IV 10 mCi of Tc 99m Tetrofosmin was given intravenously at the peak of the exercise. Thirty min following the exercise stress images were acquired. Four hour after 20mCi of Tc99m Tetrofosmin was administered in resting condition & thirty min after, images were acquired.

These reveal sizeable areas of stress perfusion defects involving anteroseptal, inferior & posterolateral segments of myocardium without any evidence of significant reperfusion in the above mentioned segments. However mild reperfusion is only appreciated confined to the basal slices. Uniform stress perfusion pattern is seen in lateral segment only. This study suggests that the anteroseptal and inferior segment including the posterior part do not show any evidence of viable reversible myocardium there by giving an important information to the cardiologists that the coronary intervention to LAD territory would not bring any further benefit to the patient.

 Conclusion: Coronary intervention thereby has been avoided and the patient has been on the medical line of treatment with regular follow up at the cardiac clinic . The importance of myocardial perfusion scan in 100 % occluded coronary diseases territory is vital to decide whether to go for revascularistion or not