Ban JE, Park HC, Park JS, Nagamoto Y, Choi JI, Lim HE, Park SW, Kim YH Electrocardiographic and electrophysiological characteristics of premature ventricular complexes associated with left ventricular dysfunction in patients without structural heart disease. Europace. 2013 May;15(5):735-41. doi: 10.1093/europace/eus371. Epub 2012 Nov 29.
Ephrem G, Levine M, Friedmann P, Schweitzer P The prognostic significance of frequency and morphology of premature ventricular complexes during ambulatory holter monitoring. Ann Noninvasive Electrocardiol. 2013 Mar;18(2):118-25. doi: 10.1111/anec.12010. Epub 2012 Nov 22.
Le VV, Mitiku T, Hadley D, Myers J, Froelicher VF Rest premature ventricular contractions on routine ECG and prognosis in heart failure patients. Ann Noninvasive Electrocardiol. 2010 Jan;15(1):56-62. doi: 10.1111/j.1542-474X.2009.00340.x.
Lee V, Hemingway H, Harb R, Crake T, Lambiase P The prognostic significance of premature ventricular complexes in adults without clinically apparent heart disease: a meta-analysis and systematic review. Heart. 2012 Sep;98(17):1290-8. doi: 10.1136/heartjnl-2012-302005. Epub 2012 Jul 10. Review.
Mountantonakis SE, Hutchinson MD Indications for implantable cardioverter-defibrillator placement in ischemic cardiomyopathy and after myocardial infarction. Curr Heart Fail Rep. 2011 Dec;8(4):252-9. doi: 10.1007/s11897-011-0069-1. Review.
Scirica BM, Braunwald E, Belardinelli L, Hedgepeth CM, Spinar J, Wang W, Qin J, Karwatowska-Prokopczuk E, Verheugt FW, Morrow DA Relationship between nonsustained ventricular tachycardia after non-ST-elevation acute coronary syndrome and sudden cardiac death: observations from the metabolic efficiency with ranolazine for less ischemia in non-ST-elevation acute coronary syndrome-thrombolysis in myocardial infarction 36 (MERLIN-TIMI 36) randomized controlled trial. Circulation. 2010 Aug 3;122(5):455-62. doi: 10.1161/CIRCULATIONAHA.110.937136. Epub 2010 Jul 19.
Scirica BM, Morrow DA, Budaj A, Dalby AJ, Mohanavelu S, Qin J, Aroesty J, Hedgepeth CM, Stone PH, Braunwald E Ischemia detected on continuous electrocardiography after acute coronary syndrome: observations from the MERLIN-TIMI 36 (Metabolic Efficiency With Ranolazine for Less Ischemia in Non-ST-Elevation Acute Coronary Syndrome-Thrombolysis In Myocardial Infarction 36) trial. J Am Coll Cardiol. 2009 Apr 21;53(16):1411-21. doi: 10.1016/j.jacc.2008.12.053.
Scirica BM, Morrow DA, Hod H, Murphy SA, Belardinelli L, Hedgepeth CM, Molhoek P, Verheugt FW, Gersh BJ, McCabe CH, Braunwald E Effect of ranolazine, an antianginal agent with novel electrophysiological properties, on the incidence of arrhythmias in patients with non ST-segment elevation acute coronary syndrome: results from the Metabolic Efficiency With Ranolazine for Less Ischemia in Non ST-Elevation Acute Coronary Syndrome Thrombolysis in Myocardial Infarction 36 (MERLIN-TIMI 36) randomized controlled trial. Circulation. 2007 Oct 9;116(15):1647-52. Epub 2007 Sep 5.
Interventional studies are often prospective and are specifically tailored to evaluate direct impacts of treatment or preventive measures on disease.
Observational studies are often retrospective and are used to assess potential causation in exposure-outcome relationships and therefore influence preventive methods.
Expanded access is a means by which manufacturers make investigational new drugs available, under certain circumstances, to treat a patient(s) with a serious disease or condition who cannot participate in a controlled clinical trial.
Clinical trials are conducted in a series of steps, called phases - each phase is designed to answer a separate research question.
Phase 1: Researchers test a new drug or treatment in a small group of people for the first time to evaluate its safety, determine a safe dosage range, and identify side effects.
Phase 2: The drug or treatment is given to a larger group of people to see if it is effective and to further evaluate its safety.
Phase 3: The drug or treatment is given to large groups of people to confirm its effectiveness, monitor side effects, compare it to commonly used treatments, and collect information that will allow the drug or treatment to be used safely.
Phase 4: Studies are done after the drug or treatment has been marketed to gather information on the drug's effect in various populations and any side effects associated with long-term use.
