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Bosisio FG, Mingardi D, Moretti E, Muzi G, Russomanno F, Tassani N, Stassaldi D, Agabiti Rosei C, De Ciuceis C, Salvetti M, Muiesan ML. Case report: Area of focus in a case of malignant hypertension. Front Cardiovasc Med 2023; 9:1108666. [PMID: 36712261 PMCID: PMC9880852 DOI: 10.3389/fcvm.2022.1108666] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2022] [Accepted: 12/16/2022] [Indexed: 01/15/2023] Open
Abstract
Malignant hypertension (MH) is characterized by severe hypertension (usually grade 3) associated with fundoscopic changes (flame hemorrhages and/or papilledema), microangiopathy and disseminated intravascular coagulation. In addition encephalopathy, acute heart failure and acute deterioration in renal function may be present. The term "malignant" reflects the very poor prognosis for this condition if untreated. When severe hypertension is associated with hypertension-mediated organ damage (HMOD) a life-threatening situation that requires immediate but careful intervention occurs (hypertensive emergency). In the last few years an increase in the number of patients with malignant hypertension has been observed, especially among those patients with black ethnicity. Limited access to treatment and the poor adherence to anti-hypertensive therapy may contribute to the development of hypertensive emergencies. It is considered appropriate to study patients in order to rule out thrombotic thrombocytopenic purpura and hemolytic uremic syndrome. In fact, the microvascular damage caused by malignant hypertension can favor intravascular hemolysis like Thrombotic Microangiopathies (TMs). TMs may present in three different clinical conditions: typical hemolytic uremic syndrome (HUS), atypical hemolytic uremic syndrome (aHUS) and thrombotic thrombocytopenic purpura (TTP). TMs can arise in the context of other pathological processes, including malignant hypertension.
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Affiliation(s)
- Francesca Gaia Bosisio
- UOC 2 Medicina, ASST Spedali Civili di Brescia, Brescia, Italy,Emergency Medicine ASST Spedali Civili Brescia, Brescia, Italy,Department of Clinical and Experimental Sciences, University of Brescia, Brescia, Italy
| | - Desirè Mingardi
- UOC 2 Medicina, ASST Spedali Civili di Brescia, Brescia, Italy,Emergency Medicine ASST Spedali Civili Brescia, Brescia, Italy,Department of Clinical and Experimental Sciences, University of Brescia, Brescia, Italy
| | - Elisabetta Moretti
- UOC 2 Medicina, ASST Spedali Civili di Brescia, Brescia, Italy,Emergency Medicine ASST Spedali Civili Brescia, Brescia, Italy,Department of Clinical and Experimental Sciences, University of Brescia, Brescia, Italy
| | - Giorgia Muzi
- UOC 2 Medicina, ASST Spedali Civili di Brescia, Brescia, Italy,Emergency Medicine ASST Spedali Civili Brescia, Brescia, Italy,Department of Clinical and Experimental Sciences, University of Brescia, Brescia, Italy
| | - Francesco Russomanno
- UOC 2 Medicina, ASST Spedali Civili di Brescia, Brescia, Italy,Department of Clinical and Experimental Sciences, University of Brescia, Brescia, Italy
| | - Nicola Tassani
- UOC 2 Medicina, ASST Spedali Civili di Brescia, Brescia, Italy,Emergency Medicine ASST Spedali Civili Brescia, Brescia, Italy,Department of Clinical and Experimental Sciences, University of Brescia, Brescia, Italy
| | | | - Claudia Agabiti Rosei
- UOC 2 Medicina, ASST Spedali Civili di Brescia, Brescia, Italy,Department of Clinical and Experimental Sciences, University of Brescia, Brescia, Italy
| | - Carolina De Ciuceis
- UOC 2 Medicina, ASST Spedali Civili di Brescia, Brescia, Italy,Department of Clinical and Experimental Sciences, University of Brescia, Brescia, Italy
| | - Massimo Salvetti
- Emergency Medicine ASST Spedali Civili Brescia, Brescia, Italy,Department of Clinical and Experimental Sciences, University of Brescia, Brescia, Italy
| | - Maria Lorenza Muiesan
- UOC 2 Medicina, ASST Spedali Civili di Brescia, Brescia, Italy,Department of Clinical and Experimental Sciences, University of Brescia, Brescia, Italy,*Correspondence: Maria Lorenza Muiesan,
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2
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Filippone EJ, Foy AJ, Naccarelli GV. The diastolic blood pressure J-curve revisited: An update. AMERICAN HEART JOURNAL PLUS : CARDIOLOGY RESEARCH AND PRACTICE 2021; 12:100065. [PMID: 38559601 PMCID: PMC10978147 DOI: 10.1016/j.ahjo.2021.100065] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Revised: 10/04/2021] [Accepted: 10/15/2021] [Indexed: 04/04/2024]
Abstract
Hypertension remains a leading cause of morbidity and mortality. Recent treatment guidelines stress more strict systolic blood pressure (SBP) targets without regard for abnormally low achieved diastolic blood pressures (DBP). However, as DBP falls below a critical level, adverse events increase, the so-called J-shaped curve. Proponents argue that the low DBP is causative due to reduced coronary perfusion during diastole with obstructive coronary artery disease (CAD), whereas others postulate the J-curve represents reverse causality from underlying comorbidity. Most data are observational, derived from population-based cohorts or post-hoc analyses of randomized controlled trials (RCT) conducted for other reasons. The purpose of this review is to analyze the observational studies performed over the last decade addressing the J-curve, with consideration of earlier data. Overall, a J-curve exists, but it remains uncertain whether low DBP is causative or instead reflects reverse causation from either diseased vasculature (widened pulse pressure) or severe underlying comorbidity. The most convincing data for causation come from studies restricted to patients with documented CAD, with evidence suggesting revascularization may mitigate risk. RCTs are needed to determine if a low DBP should preclude intensification of therapy, especially with documented CAD. Firm recommendations cannot be made with contemporary data.
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Affiliation(s)
- Edward J. Filippone
- Division of Nephrology, Department of Medicine, Sidney Kimmel Medical College at Thomas Jefferson University, Philadelphia, PA, USA
| | - Andrew J. Foy
- Department of Medicine, Penn State University Heart and Vascular Institute, Penn State M.S Hershey Medical Center and College of Medicine, Hershey, PA, USA
| | - Gerald V. Naccarelli
- Department of Medicine, Penn State University Heart and Vascular Institute, Penn State M.S Hershey Medical Center and College of Medicine, Hershey, PA, USA
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3
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Koracevic G, Stojanovic M, Kostic T, Lovic D, Tomasevic M, Jankovic-Tomasevic R. Unsolved Problem: (Isolated) Systolic Hypertension with Diastolic Blood Pressure below the Safety Margin. Med Princ Pract 2020; 29:301-309. [PMID: 32380500 PMCID: PMC7445659 DOI: 10.1159/000508462] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/13/2019] [Accepted: 04/21/2020] [Indexed: 11/19/2022] Open
Abstract
The problem of high systolic blood pressure (sBP) combined with low diastolic blood pressure (dBP) requires attention because sBP is directly and continuously related to the most important criterion, i.e., all-cause mortality, whereas dBP becomes inversely related to it after the age of 50-60 years. The European Society of Cardiology and European Society of -Hypertension (ESC/ESH) 2018 guidelines for hypertension (HTN) are helpful because they recommend a lower safety cut-off for in-treatment dBP. To prevent tissue hypoperfusion, these guidelines recommend that dBP should be ≥70 mm Hg during treatment. A patient with very elevated sBP (e.g., 220 mm Hg) and low dBP (e.g., 65 mm Hg) is difficult to treat if one strictly follows the guidelines. In this situation, the sBP is a clear indication for antihypertensive treatment, but the dBP is a relative contraindication (as it is <70 mm Hg, a safety margin recognized by the 2018 ESC/ESH guidelines). The dilemma about whether or not to treat isolated systolic hypertension (SH) patients with low dBP (<70 mm Hg) is evident from the fact that almost half (45%) remain untreated. This is a common occurrence and identifying this problem is the first step to solving it. We suggest that an adequate search and analysis should be performed, starting from the exploration of the prognosis of the isolated (I)SH subset of patients with a very low dBP (<70 mm Hg) at the beginning of already performed randomized clinical trials.
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Affiliation(s)
- Goran Koracevic
- Department for Cardiovascular Diseases, Clinical Center Nis, Nis, Serbia
- Faculty of Medicine, University of Nis, Nis, Serbia
| | - Milovan Stojanovic
- Institute for Treatment and Rehabilitation Niska Banja, Niska Banja, Serbia,
| | - Tomislav Kostic
- Department for Cardiovascular Diseases, Clinical Center Nis, Nis, Serbia
- Faculty of Medicine, University of Nis, Nis, Serbia
| | - Dragan Lovic
- Clinic for Internal Diseases Intermedica, Nis, Serbia
| | - Miloje Tomasevic
- Department of Cardiology, Clinical Center of Serbia, Belgrade, Serbia
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4
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Warren J, Nanayakkara S, Andrianopoulos N, Brennan A, Dinh D, Yudi M, Clark D, Ajani AE, Reid CM, Selkrig L, Shaw J, Hiew C, Freeman M, Kaye D, Kingwell BA, Dart AM, Duffy SJ, Reid C, Andrianopoulos N, Brennan A, Dinh D, Reid C, Ajani A, Duffy S, Clark D, Freeman M, Hiew C, Andrianopoulos N, Oqueli E, Brennan A, Duffy S, Shaw J, Walton A, Dart A, Broughton A, Federman J, Keighley C, Hengel C, Peter K, Stub D, Chan W, Warren J, O’Brien J, Selkrig L, Huntington R, Clark D, Farouque O, Horrigan M, Johns J, Oliver L, Brennan J, Chan R, Proimos G, Dortimer T, Chan B, Nadurata V, Huq R, Fernando D, Al-Fiadh A, Yudi M, Sugumar H, Ramchand J, Han H, Picardo S, Brown L, Oqueli E, Hengel C, Sharma A, Zhu B, Ryan N, Harrison T, New G, Roberts L, Freeman M, Rowe M, Proimos G, Cheong Y, Goods C, Fernando D, Teh A, Parfrey S, Ramzy J, Koshy A, Venkataraman P, Flannery D, Hiew C, Sebastian M, Yip T, Mok M, Jaworski C, Hutchinson A, Cimenkaya C, Ngu P, Khialani B, Salehi H, Turner M, Dyson J, McDonald B, Van Den Nouwelant D, Halliburton K, Reid C, Andrianopoulos N, Brennan A, Dinh D, Yan B, Ajani A, Warren R, Eccleston D, Lefkovits J, Iyer R, Gurvitch R, Wilson W, Brooks M, Biswas S, Yeoh J. Impact of Pre-Procedural Blood Pressure on Long-Term Outcomes Following Percutaneous Coronary Intervention. J Am Coll Cardiol 2019; 73:2846-2855. [DOI: 10.1016/j.jacc.2019.03.493] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Revised: 03/06/2019] [Accepted: 03/07/2019] [Indexed: 11/28/2022]
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Chrysant SG. Achieving blood pressure targets for prolonged cardiovascular health: a historical perspective. Expert Rev Cardiovasc Ther 2017; 15:517-523. [DOI: 10.1080/14779072.2017.1327348] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Steven G. Chrysant
- Department of cardiology, University of Oklahoma College of Medicine, Oklahoma City, OK, USA
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Chrysant SG. New evidence for the diastolic J-curve effect challenges the safety of intensive blood pressure control. J Clin Hypertens (Greenwich) 2017; 19:340-343. [DOI: 10.1111/jch.12962] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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7
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Tsika EP, Poulimenos LE, Boudoulas KD, Manolis AJ. The J-curve in arterial hypertension: fact or fallacy? Cardiology 2014; 129:126-35. [PMID: 25227573 DOI: 10.1159/000362381] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/29/2014] [Accepted: 03/19/2014] [Indexed: 11/19/2022]
Abstract
It is known that a large proportion of patients with arterial hypertension are undertreated. This may result in an increase of the incidence of cardiovascular events. On the other hand, aggressive reduction of blood pressure may increase cardiovascular events (J-curve phenomenon) in certain populations. This phenomenon may be seen in patients with coronary artery disease and left ventricular hypertrophy when the diastolic blood pressure decreases below 70-80 mm Hg, and the systolic blood pressure decreases below 130 mm Hg. This phenomenon is not seen in patients with stroke or renal disease. Thus, a safer and more conservative strategy should be applied in patients with coronary artery disease, left ventricular hypertrophy, elderly, and in patients with isolated systolic hypertension. This is depicted in the recently published European Society of Hypertension/European Society of Cardiology guidelines in which higher targets of blood pressure are suggested in certain cardiovascular diseases and in the elderly.
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8
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Pedrinelli R, Ballo P, Fiorentini C, Denti S, Galderisi M, Ganau A, Germanò G, Innelli P, Paini A, Perlini S, Salvetti M, Zacà V. Hypertension and acute myocardial infarction: an overview. J Cardiovasc Med (Hagerstown) 2012; 13:194-202. [PMID: 22317927 DOI: 10.2459/jcm.0b013e3283511ee2] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
History of hypertension is a frequent finding in patients with acute myocardial infarction (AMI) and its recurring association with female sex, diabetes, older age, less frequent smoking and more frequent vascular comorbidities composes a risk profile quite distinctive from the normotensive ischemic counterpart.Antecedent hypertension associates with higher rates of death and morbid events both during the early and long-term course of AMI, particularly if complicated by left ventricular dysfunction and/or congestive heart failure. Renin-angiotensin-aldosterone system blockade, through either angiotensin-converting enzyme inhibition, angiotensin II receptor blockade or aldosterone antagonism, exerts particular benefits in that high-risk hypertensive subgroup.In contrast to the negative implications carried by antecedent hypertension, higher systolic pressure at the onset of chest pain associates with lower mortality within 1 year from coronary occlusion, whereas increased blood pressure recorded after hemodynamic stabilization from the acute ischemic event bears inconsistent relationships with recurring coronary events in the long-term follow-up.Whether antihypertensive treatment in post-AMI hypertensive patients prevents ischemic relapses is uncertain. As a matter of fact, excessive diastolic pressure drops may jeopardize coronary perfusion and predispose to new acute coronary events, although the precise cause-effect mechanisms underlying this phenomenon need further evaluation.
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Affiliation(s)
- Roberto Pedrinelli
- Dipartimento Cardio Toracico e Vascolare, Universita' Di Pisa, 56100 Pisa, Italy.
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9
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Evidence for aggressive blood pressure-lowering goals in patients with coronary artery disease. Curr Atheroscler Rep 2010; 12:134-9. [PMID: 20425249 DOI: 10.1007/s11883-010-0094-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Lowering blood pressure (BP) reduces the risk of major cardiovascular mortality and morbidity. Current consensus targets for BP reduction are less than 140/90 mm Hg in uncomplicated hypertension and less than 130/80 mm Hg in those patients with diabetes, chronic kidney disease, and coronary artery disease or in those who are at high risk for developing coronary artery disease (defined as a Framingham risk score of > or = 10%). There is solid epidemiologic evidence for lower BP targets, supported by some clinical studies with surrogate end points. On the other hand, there are meager data from clinical trials using hard end points, and there is a concern that overly aggressive BP lowering, especially of diastolic BP, may impair coronary perfusion, particularly in patients with left ventricular hypertrophy and/or coronary artery disease. This review evaluates the evidence for the benefit of lower BP targets in hypertension management.
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10
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The J-curve between blood pressure and coronary artery disease or essential hypertension: exactly how essential? J Am Coll Cardiol 2009; 54:1827-34. [PMID: 19892233 DOI: 10.1016/j.jacc.2009.05.073] [Citation(s) in RCA: 170] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/11/2008] [Revised: 04/10/2009] [Accepted: 05/06/2009] [Indexed: 01/05/2023]
Abstract
The topic of the J-curve relationship between blood pressure and coronary artery disease (CAD) has been the subject of much controversy for the past decades. An inverse relationship between diastolic pressure and adverse cardiac ischemic events (i.e., the lower the diastolic pressure the greater the risk of coronary heart disease and adverse outcomes) has been observed in numerous studies. This effect is even more pronounced in patients with underlying CAD. Indeed, a J-shaped relationship between diastolic pressure and coronary events was documented in treated patients with CAD in most large trials that scrutinized this relationship. In contrast to any other vascular bed, the coronary circulation receives its perfusion mostly during diastole; hence, an excessive decrease in diastolic pressure can significantly hamper perfusion. This adverse effect of too low a diastolic pressure on coronary heart disease leaves the practicing physician with the disturbing possibility that, in patients at risk, lowering blood pressure to levels that prevent stroke or renal disease might actually precipitate myocardial ischemia. However, these concerns should not deter physicians from pursuing a more aggressive control of hypertension, because currently blood pressure is brought to recommended target levels in only approximately one-third of patients.
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Tamborini G, Pepi M, Celeste F, Muratori M, Susini F, Maltagliati A, Veglia F. Incidence and characteristics of left ventricular false tendons and trabeculations in the normal and pathologic heart by second harmonic echocardiography. J Am Soc Echocardiogr 2004; 17:367-74. [PMID: 15044872 DOI: 10.1016/j.echo.2003.12.020] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
We sought to review echocardiographic incidence of anomalous images (AI) as false tendons and trabeculations of the left ventricle (LV) in light of recent advancements in echocardiographic evaluation of heart anatomy. In 1580 patients the presence of false tendons, trabeculations, or thrombi was evaluated with transthoracic echocardiography and correlated to clinical characteristics and echocardiographic parameters. Incidence of AI was 46.7% (75% false tendons, 23% trabeculations, 2% thrombi), slightly higher in pathologic (48.9%) than in normal hearts (40.8%). AI were more frequent in male patients (52%) than in female patients (39.7%) and associated with LV dilatation, hypertrophy, and systolic dysfunction. False tendons and trabeculations were not related to age. Male sex was the most significant independent predictor of AI. In 2 patients, isolated LV noncompaction of myocardium was diagnosed and confirmed by magnetic resonance imaging. This study shows a high prevalence of AI for patients with and without pathologic hearts suggesting the need of updating LV echocardiographic anatomy. It also emphasizes the necessity for an awareness of these anatomic variants when evaluating patients for mural thrombi and cardiomyopathies.
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Affiliation(s)
- Gloria Tamborini
- Centro Cardiologico Monzino, I.R.C.C.S, Institute of Cardiology, University of Milan, Italy.
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12
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Abstract
The J-curve debate has continued for 25 years. Dependency upon observational and retrospective studies has confused the issue; only the full publication of data from the prospective, randomized Hypertension Optimal Treatment (HOT) study has thrown genuine light on the problem. Many examples of the J-curve relationship between blood pressure and cardiovascular/noncardiovascular events are due to reverse causality, where underlying disease (eg, poor left ventricular function, poor general health, poorly compliant/stiff arteries) is the cause of both the low blood pressure and the increased risk of both cardiovascular and noncardiovascular events. The J-curve in patients with stiff arteries (wide pulse pressure) may be exacerbated by treatment. From the full publication of the HOT study database it is now reasonable to conclude that for nonischemic hypertensive subjects the therapeutic lowering of diastolic blood pressure (DBP) to the low 80s mm Hg is beneficial, but it is safe (though unproductive) to go lower. However, in the presence of coronary artery disease (limited coronary flow reserve) there is a J-curve relationship between treated DBP and myocardial infarction, but not for stroke. In such high-risk (for myocardial infarction) cases it would be prudent to avoid lowering DBP to below the low 80s mm Hg.
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13
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Avanzini F, Ferrario G, Santoro L, Peci P, Giani P, Santoro E, Franzosi MG, Tognoni G. Risks and benefits of early treatment of acute myocardial infarction with an angiotensin-converting enzyme inhibitor in patients with a history of arterial hypertension: analysis of the GISSI-3 database. Am Heart J 2002; 144:1018-25. [PMID: 12486426 DOI: 10.1067/mhj.2002.126739] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
BACKGROUND Many trials have proved the benefits of early systematic treatment with angiotensin-converting enzyme inhibitors in patients with acute myocardial infarction (AMI). Pathophysiological studies, however, suggest potential harm in excessive reduction of blood pressure (BP) in hypertensive patients with ischemic heart disease. METHODS We analyzed data from the GISSI-3 (Gruppo Italiano per lo Studio della Sopravvivenza nell'Infarto miocardico) trial to assess the effects of early treatment with angiotensin-converting enzyme inhibitors during AMI in patients with a history of hypertension compared with normotensive patients. The trial randomly assigned 19,394 patients to 6 weeks of lisinopril treatment or control, starting treatment within 24 hours of AMI onset. RESULTS In the 10,661 normotensive patients, lisinopril significantly reduced lethal events, but in the 7362 hypertensive patients, a higher rate of lethal events was reported the first day of treatment, and the benefits only appeared subsequently. These results may be attributable to the subgroup of 1165 hypertensive patients with low baseline systolic BP (lower quintile, BP <120 mm Hg), in whom critical hypotension was more prone to develop after lisinopril treatment. In fact, these patients showed a higher mortality rate as the result of an excess of cardiogenic shock during the first day of lisinopril treatment (odds ratio 3.07, 95% CI 1.39-6.77) and a persistent, unfavorable death trend after 6 weeks. CONCLUSIONS These data suggest that caution should be exercised when using lisinopril in the acute phase of a myocardial infarction in patients with a history of hypertension but low systolic BP at presentation.
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Affiliation(s)
- Fausto Avanzini
- Department of Cardiovascular Research, Istituto di Ricerche Farmacologiche, Mario Negri, Milano, Italy.
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14
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Tamborini G, Maltagliati A, Trupiano L, Berna G, Sisillo E, Salvi L, Pepi M. Lowering of blood pressure and coronary blood flow in isolated systolic hypertension. Coron Artery Dis 2001; 12:259-65. [PMID: 11428534 DOI: 10.1097/00019501-200106000-00001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND In essential hypertension, the lower limit of autoregulation of coronary flow shifts to higher perfusion and the hypertensive ventricle is at a higher than normal risk of ischemia, and less able to tolerate acute reduction of coronary perfusion pressure. Little is known about pattern of coronary flow in isolated systolic hypertension, a pathologic condition in which the elevated systolic blood pressure is associated with a lower than normal vascular compliance and normal or slightly greater than normal mean arterial pressure and vascular resistance. OBJECTIVE To evaluate the effects of rapid normalization of blood pressure on coronary blood flow in isolated systolic hypertension. METHODS We subjected 20 patients with isolated systolic hypertension to intraoperative hemodynamic and transesophageal echocardiographic monitoring during peripheral vascular surgery. Coronary flow velocity integrals and diameters in the left anterior descending coronary artery were evaluated under baseline conditions and after normalization of blood pressure, which occurred spontaneously during anesthesia (10 cases; group 1A) or was induced by infusion of nitrate (10 cases, group 1B). RESULTS After normalization of systolic blood pressure integrals decreased significantly only for patients in group 1A; percentage changes of diameter were significantly greater for patients in group 1B. Therefore, coronary blood flow after normalization of systolic blood pressure increased for patients in group 1B (by 28+/-25%) and decreased for patients in group 1A (by 30+/-21%). Changes in integrals were inversely related to those in diameter (r= -0.72, P < 0.001); for patients in group 1A changes in coronary perfusion pressure and diameter were related to those of integrals (r= 0.94; P < 0.0005). CONCLUSIONS In isolated systolic hypertension, despite there being similar changes of the systolic blood pressure, administration of nitrates caused a marked increase of coronary flow through direct effects on coronary circulation, whereas spontaneous normotension was associated with a significant reduction of coronary flow.
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Affiliation(s)
- G Tamborini
- Centro Cardiologico, Fondazione Monzino, IRCCS, Centro di Studio per le Ricerche Cardiovascolari del CNR, Milan, Italy.
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15
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Maltagliati A, Berti M, Muratori M, Tamborini G, Zavalloni D, Berna G, Pepi M. Exercise echocardiography versus exercise electrocardiography in the diagnosis of coronary artery disease in hypertension. Am J Hypertens 2000; 13:796-801. [PMID: 10933572 DOI: 10.1016/s0895-7061(00)00247-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
In hypertension, coronary artery disease (CAD) can be overestimated by stress electrocardiography (ECG) and scintigraphy due to frequent false-positive results. Exercise tests are also limited by an excessive blood pressure increase, and pharmacologic pressure normalization decreases the accuracy of the test. The aim of this study was to assess the accuracy of exercise echocardiography as an alternative test for CAD detection in hypertension, both before and after adequate blood pressure control. We studied 59 hypertensive and 59 normotensive patients undergoing coronary angiography for chest pain. Upright bicycle exercise ECG and echocardiographic tests were performed in each group in the absence of therapy; in hypertensives, the tests were repeated a day apart after blood pressure normalization with sublingual nifedipine. Significant CAD (lumen narrowing >50%) was detected in 22 hypertensive and 41 normotensive patients. In the two groups, sensitivity, specificity, and diagnostic accuracy of exercise echocardiography performed before treatment were not statistically different (95%, 94%, 94% in hypertensives and 82%, 77%, 83% in normotensives, respectively), but were significantly higher than for the exercise ECG test (68%, 70%, and 69%, respectively). After blood pressure lowering, exercise echocardiography sensitivity slightly decreased (91%), whereas specificity (100%) and diagnostic accuracy (96%) did not vary; on the contrary, exercise ECG sensitivity decreased to 45%. Therefore, according to our data, exercise echocardiography can be an accurate test and more reliable than exercise ECG to detect CAD in normotensives as well as in hypertensives. Normalization of blood pressure with nifedipine does not affect its accuracy, but markedly reduces the sensitivity of exercise ECG.
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Affiliation(s)
- A Maltagliati
- Istituto di Cardiologia dell'Universita' degli Studi, Fondazione I. Monzino, IRCCS, Centro di Studio per le Ricerche Cardiovascolari del Consiglio Nazionale delle Ricerche, Milan, Italy.
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16
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Owens P, O'Brien E. Hypotension in patients with coronary disease: can profound hypotensive events cause myocardial ischaemic events? Heart 1999; 82:477-81. [PMID: 10490564 PMCID: PMC1760270 DOI: 10.1136/hrt.82.4.477] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
OBJECTIVE To determine whether anginal episodes might be related to extremes of hypotension in patients with ischaemic heart disease taking drugs to treat angina and heart failure. DESIGN AND SETTING Observational study of patients with ischaemic heart disease attending an urban tertiary referral cardiology centre. INTERVENTIONS AND OUTCOME MEASURES A selected patient population was enrolled, having: angina on one or more hypotensive cardiovascular medications; hypotension on clinic or ambulatory measurement; and a resting ECG suitable for ambulatory monitoring. Patients had echocardiography, ambulatory blood pressure monitoring, and Holter monitoring. Hypotension induced ischaemic (HII) events were defined as episodes of ST segment ischaemia occurring at least one minute after an ambulatory blood pressure measurement (systolic/diastolic) below 100/65 mm Hg during the day, or 90/50 mm Hg at night. RESULTS 25 suitable patients were enrolled, and 107 hypotensive events were documented. 40 ST events occurred in 14 patients, of which a quarter were symptomatic. Fourteen HII events occurred in eight patients, with 13 of the 14 preceded by a fall in diastolic pressure (median diastolic pressure 57.5 mm Hg, interquartile range 11, maximum 72 mm Hg, minimum 45 mm Hg), and six preceded by a fall in systolic pressure (chi(2) = 11.9, p < 0.001). ST events were significantly associated with preceding hypotensive events (chi(2) = 40.2, p < 0.0001). Patients with HII events were more frequently taking multiple hypotensive drug regimens (8/8 v 9/17, chi(2) = 5.54, p = 0.022). CONCLUSIONS In patients with ischaemic heart disease and hypotension, symptomatic and silent ischaemia occurred in a temporally causal relation with hypotension, particularly for diastolic pressures, suggesting that patients with coronary disease may be susceptible to ischaemic events incurred as a result of low blood pressure caused by excessive hypotensive drug treatment.
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Affiliation(s)
- P Owens
- Blood Pressure Unit, Beaumont Hospital, Dublin, Ireland.
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17
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Pierdomenico SD, Bucci A, Costantini F, Lapenna D, Cuccurullo F, Mezzetti A. Circadian blood pressure changes and myocardial ischemia in hypertensive patients with coronary artery disease. J Am Coll Cardiol 1998; 31:1627-34. [PMID: 9626844 DOI: 10.1016/s0735-1097(98)00163-6] [Citation(s) in RCA: 72] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
OBJECTIVES We sought to evaluate whether different circadian blood pressure (BP) changes could influence the occurrence of ischemic episodes in untreated and treated hypertensive patients with stable coronary artery disease (CAD). BACKGROUND In hypertensive patients with CAD the occurrence of myocardial ischemia could be influenced by either high or low BP values. Ambulatory monitoring has shown that circadian BP profile is not uniform in hypertensive patients. METHODS Twenty-one patients with a nighttime BP fall < 10% ("nondippers"), 35 with a nighttime BP fall between > 10% and < 20% ("dippers") and 14 with a nighttime BP fall > 20% ("overdippers") with CAD underwent simultaneous ambulatory BP and electrocardiographic monitoring before and during drug therapy with nitrates and atenolol or verapamil in a prospective, randomized, open, blinded end point design. RESULTS Daytime BP was not significantly different among the groups both before and during therapy. Nighttime BP was different by definition. Treatment significantly reduced BP values in each group (p < 0.05). Daytime ischemic episodes did not differ among the groups either before or during therapy. Drug therapy significantly reduced daytime ischemia (p < 0.05). In untreated patients, nighttime ischemia was more frequent in nondippers than in dippers and overdippers (p < 0.05). Drug therapy significantly reduced nocturnal ischemia in nondippers (p < 0.05), had no significant effect in dippers and significantly increased nighttime ischemia in overdippers (p < 0.05). During treatment, nighttime ischemia was more frequent in overdippers than in dippers and nondippers (p < 0.05). The same results were achieved when ischemic episodes were defined with more restrictive criteria (ST segment depression > or = 2 mm). CONCLUSIONS Circadian BP changes can influence the occurrence of myocardial ischemia in untreated and treated hypertensive patients with CAD. Nocturnal ischemia was found to be more frequent in nondippers among untreated patients and in overdippers among treated patients, potentially suggesting different therapeutic approaches based on circadian BP profile.
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Affiliation(s)
- S D Pierdomenico
- Centro per lo Studio dell'Ipertensione Arteriosa, delle Dislipidemie e dell'Arteriosclerosi, Dipartimento di Medicina e Scienze dell'Invecchiamento, University G. D'Annunzio, Chieti, Italy.
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18
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Affiliation(s)
- B Olutade
- Emory University School of Medicine, Department of Medicine, Atlanta, Georgia, USA
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19
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Abstract
BACKGROUND Left ventricular hypertrophy is associated with an increased risk of cardiovascular morbidity and mortality. Previous studies have shown that patients with left ventricular hypertrophy develop electrocardiographic changes and left ventricular dysfunction during acute hypotension, and suggest that the lower end of autoregulation may be shifted upwards. AIM To measure coronary blood flow (velocity) and flow reserve during acute hypotension in patients with left ventricular hypertrophy. PATIENTS Eight patients with atypical chest pain and seven with hypertensive left ventricular hypertrophy; all with angiographically normal epicardial vessels. SETTING Tertiary referral centre. METHODS The physiological range of blood pressure was determined by previous ambulatory monitoring. Left ventricular mass was determined by echocardiography. At cardiac catheterisation, left coronary blood flow velocity was measured using a Judkins style Doppler tipped catheter. During acute hypotension with sodium nitroprusside, coronary blood flow velocity was recorded at rest and during maximal hyperaemia induced by intracoronary injection of adenosine. Quantitative coronary angiography was performed manually. RESULTS For both groups coronary blood flow velocity remained relatively constant over a range of physiological diastolic blood pressures and showed a steep relation with diastolic blood pressure during maximal hyperaemia with intracoronary adenosine. Absolute coronary blood flow (calculated from quantitative angiographic data), standardised for left ventricular mass, showed reduced flow in the hypertensive group at rest and during maximal vasodilatation. CONCLUSION The results are consistent with an inadequate blood supply to the hypertrophied heart, but no upward shift of the lower end of the autoregulatory range was observed.
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Affiliation(s)
- D R Wallbridge
- Department of Medical Cardiology, Royal Infirmary, Glasgow
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20
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Annila PA, Lindgren L, Loula P, Scheinin M, Yli-Hankala AM. The effect of skin incision followed by alfentanil on catecholamine levels and on the T-wave amplitude of ECG during isoflurane anaesthesia. INTERNATIONAL JOURNAL OF CLINICAL MONITORING AND COMPUTING 1995; 12:205-11. [PMID: 8820326 DOI: 10.1007/bf01207200] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Haemodynamic, ECG T-wave amplitude and plasma potassium changes and plasma catecholamine responses to skin incision followed by alfentanil were studied in 24 ASA I patients. Propofol and vecuronium were used without anticholinergics for induction of anaesthesia followed by isoflurane in 02/air. End-tidal isoflurane concentration was kept constant (0.7%) for 30 min before the skin incision. Five min after the skin incision alfentanil 30 mu g kg-1 was given. Blood samples for catecholamines and plasma potassium concentrations were drawn from right ventricle of the heart one minute before and after the skin incision and two minutes after alfentanil. Heart rate, systolic and diastolic arterial pressures increased after the skin incision (P < 0.001), and decreased after alfentanil (P < 0.001). Plasma adrenaline and noradrenaline concentrations increased slightly after the skin incision (P < 0.05 and P < 0.01, respectively). Noradrenaline levels continued to increase after alfentanil (P < 0.001) despite totally abolished haemodynamic responses to the skin incision. ECG T-wave amplitude changes, measured as R/T ratio, did not correlate to the changes in plasma catecholamine levels: both rapid increases and decreases in R/T ratio were seen. No plasma potassium changes were seen during the trial. T-wave changes, occurring in seconds after the skin incision, are probably produced by a direct catecholamine release from cardiac sympathetic nerve endings.
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Affiliation(s)
- P A Annila
- Medical School, University of Tampere, Finland
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21
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Abstract
Coronary flow is maintained in the face of changing perfusion pressure (approximates to diastolic blood pressure [DBP]) by the process of autoregulation. A normal coronary artery is able to dilate fivefold (coronary flow reserve of 5); by contrast, coronary flow reserve falls in the presence of left ventricular hypertrophy [LVH] and/or coronary artery disease. Thus a fall in DBP that is normally well tolerated causes a fall in coronary flow, ECG changes, and left ventricular dysfunction in the presence of LVH and coronary artery disease. Such high-risk patients exhibit a J-curve relationship between DBP and death from coronary artery disease; lowering DBP (phase 5) to below the mid 80s would be imprudent in such patients.
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22
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Cruickshank JM. Blood pressure and myocardial infarction. Low blood pressure can be hazardous. BMJ (CLINICAL RESEARCH ED.) 1994; 308:1301-2. [PMID: 8205034 PMCID: PMC2540189 DOI: 10.1136/bmj.308.6939.1301a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
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23
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Stanton A, O'Brien E. Noninvasive 24 hour ambulatory blood pressure monitoring: current status. Postgrad Med J 1993; 69:255-67. [PMID: 8321789 PMCID: PMC2399641 DOI: 10.1136/pgmj.69.810.255] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- A Stanton
- Blood Pressure Unit, Beaumont Hospital, Dublin, Ireland
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24
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25
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Hall WD. Hypertension in the elderly with a special focus on treatment with angiotensin-converting enzyme inhibitors and calcium antagonists. Am J Cardiol 1992; 69:33E-42E. [PMID: 1575176 DOI: 10.1016/0002-9149(92)90016-r] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Age-related changes (e.g., decrease in plasma renin activity and total body potassium, increase in plasma catecholamines, volume depletion) need to be taken into account when selecting an antihypertensive agent for the elderly patient. A number of large scale clinical trials (e.g., Systolic Hypertension in the Elderly Program, Veterans Administration Cooperative Study, European Working Party on High Blood Pressure in the Elderly) have demonstrated that antihypertensive therapy with diuretics substantially reduced cardiovascular mortality and stroke incidence. However, since diuretics, even potassium-sparing agents, may induce hypokalemia, newer antihypertensive agents (angiotensin-converting enzyme [ACE] inhibitors and calcium antagonists) may also be appropriate as first-line monotherapy for this patient population. ACE inhibitors are effective antihypertensive agents and are associated with a lower rate of adverse effects than diuretics, beta blockers, and centrally acting agents. Nevertheless, periodic monitoring of serum potassium, creatinine levels, and renal function is advisable. An important feature of calcium antagonists is that they lower blood pressure with no negative effect on serum lipids or glucose metabolism. Typically, they have few side effects, peripheral edema being the most commonly reported. A recent double-blind randomized study comparing a new sustained release nifedipine formulation and the ACE inhibitor lisinopril found the 2 drugs equivalent in efficacy with no differences in the rate of adverse events.
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Affiliation(s)
- W D Hall
- Division of Hypertension, Emory University School of Medicine, Atlanta, Georgia
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26
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Smolich JJ, Weissberg PL, Friberg P, Broughton A, Korner PI. Left ventricular blood flow during aortic pressure reduction in hypertensive dogs. Hypertension 1991; 18:665-73. [PMID: 1834553 DOI: 10.1161/01.hyp.18.5.665] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
We measured left ventricular blood flow with radioactive microspheres during aortic pressure reduction in 10 open-chest, anesthetized dogs with left ventricular hypertrophy due to chronic hypertension and in 10 matched normotensive dogs. Heart rate and left atrial pressure were held constant, and autonomic reflexes were abolished with ganglionic blockade. Aortic diastolic pressure was lowered from baseline to 90, 75, and 60 mm Hg with an arteriovenous fistula. During aortic pressure reduction, a stepwise decline in the endocardial-to-epicardial flow ratio in hypertrophied hearts from 1.23 +/- 0.04 at baseline to 0.96 +/- 0.09 at a diastolic pressure of 75 mm Hg parallelled that in normal hearts and was not associated with any deterioration in left ventricular performance. However, a further fall in the endocardial-to-epicardial flow ratio to 0.76 +/- 0.10 at a diastolic pressure of 60 mm Hg in hypertrophied hearts exceeded that in normal hearts (0.92 +/- 0.05, p less than 0.05) and was accompanied by evidence of left ventricular isovolumic and end-systolic dysfunction. We conclude that in hearts with pressure-overload left ventricular hypertrophy, aortic pressure reduction causes a transmural blood flow redistribution from subendocardial to subepicardial muscle layers. At moderately low aortic pressures, this redistribution is more pronounced than in normal hearts and is associated with functional evidence of myocardial ischemia.
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Affiliation(s)
- J J Smolich
- Baker Medical Research Institute, Melbourne, Australia
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27
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Polese A, De Cesare N, Montorsi P, Fabbiocchi F, Guazzi M, Loaldi A, Guazzi MD. Upward shift of the lower range of coronary flow autoregulation in hypertensive patients with hypertrophy of the left ventricle. Circulation 1991; 83:845-53. [PMID: 1825626 DOI: 10.1161/01.cir.83.3.845] [Citation(s) in RCA: 132] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
BACKGROUND At any given perfusion pressure, coronary reserve is expressed by the difference between autoregulated and maximally vasodilated flow. In hypertension the raised coronary resistance reduces the steepness of the pressure-flow relationship at maximal vasodilatation. In the presence of cardiac hypertrophy the line of autoregulated flow becomes higher. For these reasons coronary reserve is reduced and the point at which baseline flow approaches the maximal achievable flow might be shifted to a higher perfusion pressure. Thus, any reduction below this elevated and critical value of pressure would lower the coronary flow. METHODS AND RESULTS The investigated patients were normotensive (controls, nine) and hypertensive with normal (group I, seven) or augmented LV mass index because of concentric LV hypertrophy (group II, eight). All had effort-induced angina and angiographically normal left epicardial branches. Flow in the great cardiac vein was measured by thermodilution in the baseline and during stepwise (5 mm Hg every 5 minutes) decrease of the coronary perfusion pressure with a titrated nitroprusside i.v. infusion; perfusion pressures of 60 mm Hg in the controls and 70 mm Hg in the hypertensives were taken as end points. Baseline flow averaged 102 ml/min in normotensives, 104 ml/min in hypertensive group I and 148 ml/min in hypertensive group II. At the end points flow was similar to baseline in the controls and group I. In group II coronary flow started to decline and myocardial O2 extraction started to slightly but significantly rise at perfusion pressures of 90-80 mm Hg; at the end point flow was reduced by 26% (p less than 0.01 from baseline). The perfusion patterns did not seem to be related to the changes in tension-time index and heart rate. CONCLUSIONS The association of high blood pressure (reduced ability of the coronary arterioles to dilate) and hypertrophy of the myocardium (augmented baseline coronary flow) may shift the point of exhaustion of coronary reserve to a higher perfusion pressure and make the myocardium vulnerable to treatment-induced relative hypertension.
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Affiliation(s)
- A Polese
- Istituto di Cardiologia dell' Università degli Studi Milano, Italy
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Picano E, Lucarini AR, Lattanzi F, Marini C, Distante A, Salvetti A, L'Abbate A. ST segment depression elicited by dipyridamole infusion in asymptomatic hypertensive patients. Hypertension 1990; 16:19-25. [PMID: 2365445 DOI: 10.1161/01.hyp.16.1.19] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
In asymptomatic patients with essential hypertension, electrocardiographic changes suggestive of myocardial ischemia can be elicited by rapid pressure lowering or by pronounced coronary arteriolar dilation. The aim of this study was to assess whether dipyridamole infusion might induce ischemic-like electrocardiographic changes in asymptomatic essential hypertensive patients and to describe the clinical and echocardiographic correlates possibly associated with this response. We therefore studied a control group of 20 normotensive individuals and a group of 28 asymptomatic patients with mild-to-moderate essential hypertension. All underwent dipyridamole-echocardiography testing (12-lead electrocardiogram and two-dimensional echocardiographic monitoring with dipyridamole infusion, 0.84 mg/kg over 10'). No patient showed transient regional dyssynergy during dipyridamole infusion. None of the normotensive and 10 of 28 of the hypertensive participants had horizontal or downsloping ST segment depression more than 0.1 mV during dipyridamole (0% versus 36%, p less than 0.01). Hypertensive patients with ("responders") (n = 10) and without ("nonresponders") (n = 18) ST segment depression showed similar values of percent fractional shortening in baseline conditions (32 +/- 5 versus 33 +/- 6, p = NS) and at peak dipyridamole infusion (45 +/- 8 versus 43 +/- 5, p = NS). The peak early to peak late velocity ratio values (evaluated from transmitral flow tracings by Doppler technique) were also similar in baseline conditions (0.86 +/- 0.14 versus 0.94 +/- 0.30, p = NS) and at peak dipyridamole (0.72 +/- 0.15 versus 0.78 +/- 0.32, p = NS).(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- E Picano
- CNR Institute of Clinical Physiology and Clinica Medica I, University of Pisa, Italy
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Cruickshank JM. Coronary flow reserve and the J curve relation between diastolic blood pressure and myocardial infarction. BMJ (CLINICAL RESEARCH ED.) 1988; 297:1227-30. [PMID: 3145062 PMCID: PMC1834729 DOI: 10.1136/bmj.297.6658.1227] [Citation(s) in RCA: 173] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The results of several large studies of hypertension and follow up studies on insured people have indicated that the lower the blood pressure the better for longevity. These studies excluded subjects with overt ischaemia. More recently long term studies of hypertension that included patients with more severe forms of hypertension and did not exclude those with overt ischaemia have shown a J shaped relation between diastolic blood pressure during treatment and myocardial infarction; the lowest point (the J point) was at a diastolic blood pressure (phase V) between 85 and 90 mm Hg. The J curve seems to be independent of treatment, pulse pressure, and the degree of fall in diastolic blood pressure and is unlikely to be caused by poor left ventricular function. The most probable explanation is that subjects who have severe stenosis of the coronary artery as well as hypertension have a poor coronary flow reserve, which makes the myocardium vulnerable to coronary perfusion pressures that are tolerated by patients without ischaemia, particularly at high heart rates. An optimal diastolic blood pressure (phase V) for such patients is about 85 mm Hg, though particular caution is appropriate when treating very old patients (84 and over) and patients aged 60-79 who have isolated systolic hypertension.
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Abstract
Patients with critical coronary stenoses or hypertrophied ventricles have impaired coronary vasodilator reserve and are at greatest risk of myocardial ischaemia or infarction if subendocardial perfusion pressure falls below the lower threshold of bloodflow autoregulation. During sleep, antihypertensive treatment may cause coronary artery perfusion pressure to fall below these limits in such patients. Unrecognised nocturnal hypotension may be one reason why treatment has not diminished the risk of myocardial infarction in patients with hypertension.
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Affiliation(s)
- J S Floras
- Division of Cardiology, Toronto General Hospital, Canada
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