This is the big one that carries a high mortality if not treated rapidly. This results in part of the inferior wall being supplied by the LAD, as well.
Oh, my! We will get to the examples soon, but first we need to understand some more basics of anterior MIs. If the thrombus is in the proximal LAD, the septum and lateral walls will often also be involved, in addition to the anterior segments, resulting in ST segment elevation in leads V1 through V6 and perhaps lead I and aVL, as well. When the thrombus is in the mid LAD after the septal branch , the diagonal branch es may or may not be involved.
If this is the case, then the ST segment elevation will be in V3 to V6 — and not the septal leads. Here is some more terminology. Treatment for all of them is the same, regardless of what pattern it takes — that is quick coronary revascularization. This is named for obvious reasons. The J point is elevated and, along with the T wave, and it looks like a tombstone.
Do not confuse the ST segment elevation with the T wave. Look specifically where the ST segment is — waaaaay up from the baseline. Recall that the J point is where we need to measure the elevation from baseline, and the baseline is always the TP segment between the T wave and the P wave.
Below is another example of tombstoning with a slightly different shape. There is septal involvement lead V2 and a bit laterally, as well lead V5 and V6. The more examples you see, the better. There is no lateral involvement here. Although not quite a tombstone, there is still significant ST segment elevation here.
The next example below is trying to tombstone — and maybe did in lead V4. There is definite elevation of the J point in V2 to V6, at least, and minimal elevation in V1 and V6. This is a good example to quickly point out something else. The typical pattern with LVH includes deviation of the ST segment in the opposite direction of the QRS complex discordance and a typical T wave inversion pattern is present.
Enlarge 2. Early repolarization:. Early repolarization is a common finding in young, healthy individuals. It appears as mild ST segment elevation that can be diffuse, however is more prominent in the precordial leads. Enlarge 3.
Enlarge 4. With an anterior or apical aneurysm, the persistent ST elevation is in lead V1 and V2. Nitrates should not be administered in 1 patients with hypotension, 2 if there is suspicion of right ventricular infarction, 3 severe aortic stenosis, 4 hypertrophic obstructive cardiomyopathy or 5 pulmonary embolism. As with morphine, use of nitrates must not limit the use of beta blockers and ACE inhibitors these drugs affect blood pressure and heart rate.
Oral beta-blockers should be initiated during the first 24 hours after admission. Intravenous beta-blockers are only considered in patients with persistent hypertension. Beta-blockers are avoided if the patient has risk factors for cardiogenic shock. With respect to long-term treatment, beta blockers should be given to all patients in maximal tolerated dosis and continued indefinitely. Beta blockers have negative inotropic and chronotropic effect, which reduces heart rate duration of diastole is therefore prolonged , cardiac output and blood pressure.
The workload on the myocardium is reduced and the oxygen consumption and oxygen demand is reduced. Prolongation of diastole will give extra time for the myocardium to be perfused the myocardium is perfused only during diastole. Beta blockers increase survival, reduce morbidity, improve left ventricular function and may also reduce or limit infarct size.
Beta blockers presumably also protect against ventricular tachyarrhythmias ventricular tachycardia. Treatment with beta blockers should start early within 24 hours , provided that the patient is hemodynamically stable. Beta blockers may be used in patients with hypertension on presentation.
Metoprolol 5 mg IV may be given three times with 5—10 minutes intervals in the acute setting. Heart rate and blood pressure should be monitored during administration of intravenous beta blockers. If tablets are preferred, metoprolol 25 mg may be given every sixth hour until the maximal tolerated dose or mg daily is reached.
The dose is limited by bradycardia and hypotension. Patients with acute heart failure should not be give beta blockers during the acute phase. However, beta blockers should be started early when heart failure has stabilized.
Second-degree and third-degree AV block without pacemaker are contraindications. Patients with COPD chronic obstructive pulmonary disease should be given beta-1 selective agents e. A loading dose oral of aspirin mg to mg should be given immediately to all patients. Aspirin is given in the prehospital setting and before PCI. Aspirin is then continued indefinitely maintenance dose 80 mg daily. In addition to aspirin, a loading dose of an oral P2Y 12 -receptor inhibitor should also be given immediately before PCI.
The options include:. Clopidogrel is inferior to prasugrel and ticagrelol. Ticagrelol appears to cause fewer bleeding complications as compared with prasugrel.
P2Y12receptor inhibitor is continued for 12 months in patients receiving a stent during PCI. Maintenance doses are clopidogrel 75 mg daily, prasugrel 10 mg daily, and ticagrelol 90 mg twice daily. Note that the interventionist may add additional antiplatelet agents abciximab, tirofiban, eptifibatide during PCI. These drugs, however, are not administered outside of the catheterization laboratory. All patients should immediately be given aspirin loading dose of to mg and then continued indefinitely maintenance dose 80 mg daily.
Aspirin is combined with either clopidogrel, prasugrel or ticagrelol. Patients who are unable to swallow may be given mg as a suppository or 80 to mg IV. All patients should receive a maintenance dose of 80 mg daily which is continued indefinitely.
Hypersensitivity to aspirin is uncommon and in that scenario, clopidogrel may be used instead. Note that aspirin is a highly effective drug in both the acute setting and in secondary prevention to prevent re-infarction and the drug must never be terminated without careful consideration.
As noted above, optimal antiplatelet effect requires the addition of either ticagrelol, prasugrel or clopidogrel. Combining aspirin with any of these is referred to as DAPT dual antiplatelet therapy. An individual assessment of bleeding risk is warranted and DAPT should be avoided if the risk is high.
DAPT is continued for 12 months in all patients, and the indication is stronger in patients who undergo PCI with placement of stent both bare metal stents and drug eluting stents. A loading dose of mg followed by maintenance dose of 80 mg daily is recommended. The additional increase in bleeding risk is smaller with clopidogrel, as compared with prasugrel and ticagrelol.
Prasugrel is more potent than clopidogrel. Prasugrel reduces cardiovascular mortality, non-fatal acute myocardial infarction and stroke more than clopidogrel. Data from randomized trials demonstrate that prasugrel appears to be particularly effective in patients with anterior STEMI.
The loading dose is 60 mg followed by a maintenance dose of 10 mg daily. Prasugrel is contraindicated in patients with previous stroke, TIA, renal failure and liver failure. Finally, prasugrel should be used with caution in patients older than 75 years as well as those weighing less than 60 kg. Ticagrelol loading dose mg, maintenance dose 90 mg twice daily is more effective than clopidogrel and reduces cardiovascular mortality, non-fatal acute myocardial infarction and stroke.
Although the PLATO study showed that ticagrelol caused more serious bleedings, as compared with clopidogrel, the overall effect was beneficial and it was concluded that the benefits outweigh the risks.
In patients referred for primary PCI, ticagrelol is the drug of choice among the three P2Y 12 -receptor inhibitors. Patients frequently report dyspnea and, less frequently, bradycardia the first week on ticagrelol treatment. These side effects are benign and usually transient. Ticagrelol is contraindicated in patients with previous cerebral hemorrhage or liver failure clopidogrel is recommended to those patients instead.
This class of drugs is actually the most potent platelet inhibition available. However, the addition of these agents confers little benefit, which appears to be reserved for certain subgroups of patients. Anticoagulation is continued a few days after primary PCI. However, anticoagulants are not necessary thereafter, unless there are other indications e. Enoxaparin is given intravenously and is preferred over UFH.
Bivalirudin caused fewer bleedings and resulted in lower mortality. Bivalirudin is also preferred in patients with heparin induced thrombocytopenia HIT , as well as in cases with a high risk of bleeding. On the contrary, fondaparinux was associated with an increased risk of stent thrombosis. Reperfusion is accomplished by means of PCI or intravenous fibrinolysis. Successful reperfusion restores blood flow to the ischemic myocardium and halts the infarction process.
However, if PCI will be delayed by minutes or more from first medical contact , fibrinolysis should be given if it is not contraindicated.
Reperfusion refers to the restoration of blood flow perfusion in the occluded artery. There are two principal methods for achieving reperfusion in patients with acute STEMI, namely PCI percutaneous coronary intervention and fibrinolysis. PCI is by far the most effective method.
Reperfusion, with either PCI or fibrinolysis, is considered in the following situations:. As mentioned above, numerous studies conducted in the past decades have shown that PCI is superior to fibrinolysis. Guidelines recommend the following:. In any case, patients arriving to a hospital without a catheterization laboratory should be relocated to a hospital with PCI facility once the patient is hemodynamically stable.
Restoration of coronary blood flow is markedly better with PCI, as compared with fibrinolysis re-flow is greater and the risk of re-stenosis is smaller. PCI is less dependent on symptom duration fibrinolysis is dependent on symptom duration because the thrombus material reorganizes gradually and becomes less susceptible to fibrinolytic agents. Nowadays virtually all procedures include placement of a coronary stent, which may be either drug-eluting DES or not bare-metal stent, BMS.
Data suggests that DES confers a lower risk of restenosis. Fibrinolysis tenecteplase, alteplase, reteplase is very effective in lysing a thrombus if it is given early within 2 hours of symptom onset. The effect of these agents diminishes gradually because of a reorganization taking place in the thrombotic material.
If fibrinolysis is administered in the prehospital setting, it may be as effective as PCI. However, fibrinolysis frequently fails to establish a patent blood flow and the risk of re-occlusion is significant. Moreover, fibrinolysis may cause serious bleedings and even deaths due to hemorrhage.
No products in the cart. Sign in Sign up. Search for:. Introduction to ECG Interpretation. Clinical electrocardiography and ECG interpretation. Arrhythmias and arrhythmology. Mechanisms of cardiac arrhythmias: from automaticity to re-entry reentry.
Conduction Defects. Overview of atrioventricular AV blocks. Atrial and ventricular enlargement: hypertrophy and dilatation on ECG.
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