Right ventricular involvement in myocardial infarction and cardiogenic shock

CONTEXT: Right ventricular involvement in acute myocardial infarction and cardiogenic shock has received little attention by clinicians and researchers, although its pathophysiology, clinical presentation, and natural history are distinctly different from those of left ventricular infarction and associated cardiogenic shock. Right ventricular shock has important therapeutic implications for the management of patients, which need to be recognised. STARTING POINT: Investigators at the SHOCK Registry (Alice Jacobs and colleagues, J Am Coll Cardiol 2003; 341: 1273-79) evaluated 49 patients with cardiogenic shock predominantly due to right ventricular infarction and compared them with 884 patients with cardiogenic shock and predominantly left ventricular failure. Perhaps surprisingly, these investigators found that the in-hospital mortality of patients with right ventricular shock was not significantly lower than that of patients with left ventricular shock (53% vs 61%, p=0.296), despite the fact that patients with right ventricular shock were younger, with a lower prevalence of previous infarctions, fewer anterior infarct locations, and less multivessel disease. There was a shorter median time between index infarction and diagnosis of shock in patients with right ventricular shock. In multivariate analysis, right ventricular shock was not an independent predictor of lower in-hospital mortality. WHERE NEXT? The unexpectedly high mortality of patients with cardiogenic shock due to predominantly right ventricular infarction challenges the general notion that right ventricular involvement in myocardial infarction has only little relevance for patient's outcome. Therefore, more attention should be given to the detection of right ventricular involvement in acute myocardial infarction and particularly in cardiogenic shock. If right ventricular shock is diagnosed, urgent reperfusion of the infarct related artery and appropriate circulatory support are required.     

Aggressive surgical management of post-infarction angina: results of myocardial revascularization early after transmural infarction

In our Division of Cardiothoracic Surgery between 1970 and 1982, 110 patients (88 males and 22 females) had coronary artery bypass grafts (CABG) performed for unstable angina pectoris after acute transmural myocardial infarction. Fifty-one patients (mean age 59 years) had CABG within 2 weeks of myocardial infarction (Group 1); and 59 patients (mean age 56 years) (p = NS) within 6 weeks of myocardial infarction (Group 2). The incidence of preoperative arrhythmias, left ventricular ejection fraction, end-diastolic pressure, and the number of vessels diseased were similar in Groups 1 and 2. The incidence of cardiogenic shock was higher in Group 1 (16/51, 31% vs 2/59, 3% [p < 0.001]). This was also the case with the use of the intraaortic balloon (32/51, 63% vs 12/59, 20% [p < 0.001]), and the need for emergency operation (29/51, 57% vs 4/59, 7% [p < 0.001]). The mean number of grafts was 2.8 in Group 1 and 3.0 in Group 2 (p = NS). Operative mortality was 20% (10/51) in Group 1 and 7% (4/59) in Group 2 (p < 0.01). Excluding patients in cardiogenic shock, operative mortality was 0% (0/35) in Group 1 and 5% (3/57) in Group 2 (p = NS). Incidences of late death, recurrent angina, and permanent disability were similar during mean follow-up times of 3.2 years in Group 1 and 4.1 years in Group 2. Actuarial probability of survival was 96% at 1 year and 83% at 5 years. Myocardial revascularization early after transmural myocardial infarction has a low risk, especially in the absence of cardiogenic shock. These results justify an aggressive approach to unstable angina, including patients within 2 weeks of transmural infarction.     

A stepwise progression in the treatment of cardiogenic shock

Cardiogenic shock remains a deadly complication of acute myocardial infarction (MI). Early revascularization, inotropic support, and intraaortic balloon counterpulsation are the mainstays of treatment, but these are not always sufficient. New mechanical approaches, both percutaneous and surgical, are available in this high-risk population. We present a case of a young woman with a massive anterior wall MI and subsequent cardiogenic shock who was treated with advanced mechanical circulatory support. This case serves as an illustration of the stepwise escalation of mechanical support that can be applied in a patient with an acute MI complicated by refractory cardiogenic shock. We also review the literature with regard to the use of percutaneous left ventricular assist devices in the setting of cardiogenic shock.     

Cardiogenic shock complicating acute myocardial infarction: the use of coronary angioplasty and the integration of the new support devices into patient management.

Conventional therapy for cardiogenic shock complicating acute myocardial infarction continues to be associated with a high in-hospital mortality rate. Hemodynamic support with new mechanical devices and emergency coronary revascularization may alter the long-term prognosis for patients with this complication. Between July 1985 and March 1990, 68 patients presented to the University of Michigan with acute myocardial infarction and cardiogenic shock. Interventions performed included thrombolytic therapy (46%), intraaortic balloon pump counterpulsation (70%), cardiac catheterization (86%), coronary angioplasty (73%), emergency coronary artery bypass grafting/ventricular septal defect repair (15%), Hemopump insertion (11%), percutaneous cardiopulmonary support (4%) and ventricular assist device (3%). The 30-day survival rate was significantly better in patients who had successful angioplasty of the infarct-related artery than in patients with failed angioplasty (61% vs. 7%, p = 0.002) or no attempt at angioplasty (61% vs. 14%, p = 0.003). This difference was maintained over the 1-year follow-up period. The only clinical variable that predicted survival was age less than 65 years. The early use of the new support devices in 10 patients was associated with death in 8 (80%), but this poor outcome may reflect a selection bias for an especially high risk population. Collectively, these recent data continue to suggest that emergency revascularization with angioplasty may reduce the mortality rate, but further study is required to define optimal utilization and integration of new support devices.     

Results of the use of the counter-pulsation balloon in experimental post coronary oclussion cardiogenic shock in closed thorax]

An experimental study of the production of cardiogenic shock together with the results of its treatment by means of the intraaortic balloon was carried out. Cardiogenic shock was produced in dogs with closed thorax and spontaneous respiration. In 13 of the 21 dogs studied, the production of acute myocardial infarction by means of selective embolism of the left circumflex artery permitted the reproduction of a model of cardiogenic shock. Embolism was produced by injecting metalic mercury through a double catheter. Six of the 8 remaining dogs died due to accidental introduction of mercury in the anterior descending coronary artery which produced irreversible ventricular fibrillation. The other 2 died due to rupture of the ascending aorta during the maneuveres to place the coronarygraphy catheter. The 13 dogs with cardiogenic shock were treated with intraaortic balloon pumping during 3-4 hours. The left ventricular systolic pressure fell from 128 +/- 12.07 to 124 +/- 4.65 mm. Hg. The cardiac index increased by 42%. These findings confirm the fact that intraaortic balloon pumping lessens the after load. The fall of the telediastolic pressure by 20% was an index of the lessening or the preload. The aortic telediastolic pressure rose by a mean value of 32.21 mm. Hg. This raises the coronary perfusion pressure thus limiting the extension or reducing the size of the infarction. A frank reduction of the electrographic subepicardiac lesion was observed after using intraaortic balloon pumping. The mean aortic pressure only rose by 8%, the central venous pressure remained unchanged and the increase in diuresis was not estimable. The maximum dP/dt was unaltered and the Vmax. rose 17%. Two dogs were left alive after the experiment and lived for 3 and 12 days respectively. To conclude the results obtained permit us to indicate that intraaortic balloon pumping when used in dogs with this standard type of cardiogenic shock produces an important reduction of the after load, a discrete reduction of the preload and a significative increase in coronary blood flow. There were no changes in cardiac frequency and although the results of myocardial contractility were not definite, they seem to indicate a moderate improvement.     

Survivor of cardiogenic shock following acute myocardial infarction with Churg-Strauss syndrome: first angiographic documention of coronary recanalization of infarct-related arteries: a case report

A 42-year-old man was treated under a diagnosis of Churg-Strauss syndrome with predonisolone pulse therapy. Three days later, he developed cardiogenic shock following acute myocardial infarction. Coronary angiography showed total occlusions in three peripheral coronary vessels. Intraaortic balloon pumping was used to maintain hemodynamics and predonisolone pulse therapy was repeated. However, he developed cardiogenic shock again after the second pulse therapy and needed percutaneous cardiopulmonary support and intraaortic balloon pumping. Accordingly, combination therapy of predonisolone and cyclophosphamide was given. He then recovered. Follow-up angiography showed recanalization of the infarct-related arteries.     

Percutaneous ventricular assist device placement during active cardiopulmonary resuscitation for severe refractory cardiogenic shock after acute myocardial infarction

Cardiogenic shock after acute myocardial infarction is associated with a high mortality rate despite modern reperfusion methods and intra-aortic balloon pump support. For myocardial infarction patients in cardiogenic shock that is refractory to intra-aortic ballon pump counterpulsation and pressors (severe refractory cardiogenic shock), there are limited means to rapidly provide additional hemodynamic support. We present the case of a 49-year-old man who presented with an anterior wall acute myocardial infarction complicated by cardiogenic shock. After resuscitation and stabilization with intra-aortic balloon pump and pressor support, the patient underwent successful emergent percutaneous transluminal coronary angioplasty and stenting of the left anterior descending coronary artery. Forty-eight hours later, the patient again went into severe refractory cardiogenic shock; pulseless electrical activity arrest followed. Cardiopulmonary resuscitation was started, and the patient underwent urgent placement of a TandemHeart percutaneous ventricular assist device. The device enabled the reversal of terminal hemodynamic collapse during active cardiopulmonary resuscitation, subsequent stabilization of the patient, and discharge of the patient from the hospital after device removal. In this patient, the percutaneous ventricular assist device was successful in the treatment of severe refractory cardiogenic shock after acute myocardial infarction.     

Intra-aortic balloon pumping in coronary artery disease

Cardiogenic shock and severe left ventricular failure after acute myocardial infarction, refractory angina pectoris at rest either of new onset or superimposed on stable angina pectoris, or occurring in the post infarct (less than 2 weeks) period, and the suspicion of a slowly evolving infarction are the main indications for intra-aortic balloon pumping at the Thoraxcenter. 76 patients were treated with intra-aortic balloon pumping for cardiogenic shock after acute myocardial infarction and left ventricular failure, 42/76 (55%) could be weaned, 9 (12%) died within 3 months, 33 (43%) survived over 3 months, to date 29 are alive. 42 patients with refractory angina at rest were treated with intra-aortic balloon pumping. Pain relief was prompt in 41 (98%), who subsequently underwent coronary artery bypass grafting. Total myocardial infarction rate was 11% (5/42), total mortality rate was 7%. Perioperative myocardial infarction rate was 8% (4/42) and perioperative mortality was 7% (3/42). Pain relief was prompt in 14/17 patients (82%) with post infarct refractory angina. In 3 patients pain persisted despite intra-aortic balloon pumping, all sustained a myocardial infarction, 1 died, 2 other patients were excluded for surgery. 12 patients underwent coronary artery bypass grafting, none died, none developed acute myocardial infarction, 3 have mild stable angina. In 8 patients a slowly evolving myocardial infarction was suspected. Pain relief was prompt in 7/8 (88%) after institution of intra-aortic balloon pumping. Intra-aortic balloon pumping improves prognosis in cardiogenic shock after myocardial infarction, and abolishes refractory ischemic pain.     

Intraaortic balloon counterpulsation: an eleven-year review and analysis of determinants of survival

During an 11-year period ending January 1, 1985, 352 patients had insertions of an intraaortic balloon pump (IABP) as an adjunct to medical or surgical therapy. Group I, 175 patients, could not be weaned from cardiopulmonary bypass and required intraaortic balloon pump (IABP). Thirty-nine patients (22%) died in the operating room. Twenty-five patients (14%) died in the acute care unit. The remaining 111 patients (63.4%) survived and were discharged from the hospital. Group II, 104 patients, had the IABP inserted preoperatively. Indications were: postinfarction cardiogenic shock (34 patients), unstable angina (35), postinfarction angina (27), poor ventricular function (six), and prophylaxis (two). Of the 62 patients with unstable angina and postinfarction angina, 57 (92%) were successfully weaned. Of the 34 patients with postinfarction cardiogenic shock, 26 were weaned, but only 16 (47%) survived to leave the hospital. Group III, 34 patients, had the IABP inserted for postoperative hemodynamic deterioration in the acute care unit at variable times: 14 (41%) patients survived. Group IV, 39 patients, had IABP support for medical therapy. Of 24 patients with postinfarction cardiogenic shock, 12 survived. Twelve of 13 patients with unstable angina lived. Of the 352 patients, 228 (65%) were discharged from the hospital. The overall incidence of complications was 12.5%. Complications related to IABP were higher with percutaneous insertion than by femoral arteriotomy (15% vs 12%). Intraaortic balloon counterpulsation effectively unloads the failing left ventricle in weaning patients from cardiopulmonary bypass (Group I). Preoperative insertion (Group II) resulted in 92% survival in patients with both pre- and postinfarction angina. Delayed insertion (Group III) in postoperative patients gave the poorest survival (41%). In patients with postinfarction cardiogenic shock, IABP without corrective cardiac surgery was associated with a 50% survival: with corrective cardiac surgery, 16 patients (47%) survived. Left ventricular dysfunction, myocardial infarction, and timely insertion of IABP are the primary determinants of survival. Approximately one-third of patients who required IABP will die. More involved techniques for mechanical support of the failing circulation, such as ventricular assist device or total artificial heart, may increase survival.     

Appropriate indications for the use of a percutaneous cardiopulmonary support system in cases with cardiogenic shock complicating acute myocardial infarction

Percutaneous cardiopulmonary support (PCPS) is now available for hemodynamic support in patients with cardiogenic shock, but there are no guidelines for its use. The present study determined the appropriate indications for the use of the PCPS in patients with cardiogenic shock complicating acute myocardial infarction (AMI). Sixty-four consecutive patients with cardiogenic shock complicating AMI had hemodynamic support with an intraaortic balloon pump (IABP; n=38) and/or PCPS (n=26). The shock score (0-15) was calculated immediately before starting these support systems to quantify the severity of shock. Multivariate logistic regression analysis determined the clinical factors affecting in-hospital mortality. The relationship between in-hospital prognosis and the shock score was also examined in the 2 groups. The most significant factor related to the in-hospital prognosis was the shock score (p=0.0007; OR 2.16, 95% CI: 1.37-3.39). Another related factor was revascularization; however, this relationship did not reach statistical significance (p=0.069; OR 0.06). Among the 13 cases whose shock score was 4-8 (moderate shock), 5 survived in the PCPS group, but only 1 of 19 patients survived in the IABP group (p<0.05). None of the patients in either group whose shock score was more than 9 survived. The severity of shock is the most reliable independent predictor of in-hospital mortality in patients with cardiogenic shock complicating AMI. Using PCPS in patients with moderate cardiogenic shock may improve their in-hospital survival, but it must be used before the shock becomes severe.     

Complications of intraaortic balloon counterpulsation insertion in patients receiving thrombolytic therapy for acute myocardial infarction

This study retrospectively examines 38 patients who presented with acute myocardial infarction requiring intraaortic balloon pump counterpulsation. Two groups of patients were identified. Group I consisted of patients with acute myocardial infarction treated with intraaortic balloon pump without thrombolytic therapy. Group II consisted of patients treated with intraaortic balloon pump after receiving intravenous thrombolytic therapy. These groups were compared and contrasted with regard to previously identified complications associated with intraaortic balloon pump counterpulsation including loss of limb and mortality. The need for surgery, embolectomy, and drainage of hematoma were also evaluated. The need for surgery in group II (11%) and in both groups combined (7%) is lower than is generally reported in literature (range 11.6% to 34%). In addition, no patients experienced a loss of limb and no patients in the study had severe life-threatening iatrogenic morbidity or mortality. While mortality was not an end point in this study, it was noted that there was an increased survival rate in group II patients with 61% surviving until the time of hospital discharge. Also, eight out of 14 patients in group II who underwent intraaortic balloon pump counterpulsation for cardiogenic shock survived until the time of discharge. This represents a 57% survival rate for patients presenting with cardiogenic shock. We conclude that intraaortic balloon pumps can be inserted safely following thrombolytic therapy in a community hospital.     

Emergent angioplasty prevents left ventricular dilation in patients with acute anterior wall myocardial infarction and cardiogenic shock

BACKGROUND: Percutaneous transluminal coronary angioplasty (PTCA) reduces in-hospital mortality and improves long-term outcome in patients with acute myocardial infarction (MI) complicated by cardiogenic shock. However, no study has evaluated the effects of different reperfusion therapies on left ventricular (LV) dimension and cardiac function in long-term survivors of MI with cardiogenic shock. HYPOTHESIS: We investigated the effects of PTCA on the development of LV dilation in patients who survived MI complicated by cardiogenic shock. METHODS: We studied 34 patients with a first MI and cardiogenic shock in whom two-dimensional echocardiography was performed immediately after admission and 1 month after infarction. Group A consisted of 17 patients who underwent emergent PTCA during the acute phase of MI, and Group B consisted of 17 patients who did not undergo PTCA. We also studied 119 patients with a first uncomplicated acute anterior MI, including 53 who underwent PTCA (Group C) and 66 who did not (Group D). The length and wall thickness of the infarcted and noninfarcted endocardial segments were determined immediately after MI and 1 month later, and LV ejection fraction (LVEF) was measured during the chronic phase. RESULTS: The lengths of the infarcted and noninfarcted endocardial segments were significantly greater in Group B than in the other three groups (p < 0.05). The LVEF was significantly lower in Group B than in the other three groups (p < 0.05). CONCLUSIONS: We conclude that PTCA performed in patients during the acute phase of MI complicated by cardiogenic shock lowers in-hospital mortality and prevents both LV dilation and a decrease in LVEF.     

Clinical management ancillary to phase-shift balloon pumping in cardiogenic shock. Preliminary comments

Intraaortic phase-shift balloon pumping was utilized in 30 patients in cardiogenic shock secondary to acute myocardial infarction who were refractory to conventional pharmacologic therapy. The outcomes in these cases suggested that the interval from myocardial infarction to onset of shock, rather than the duration of shock, may have a significant influence on the prognosis. Of 20 patients classified as having “early” shock, 3 died as a result of factors related to the procedure. Of the remaining 17 patients, the condition of 15 (88 percent) improved to the point that intraaortic balloon pumping could be discontinued. Nine of these patients were long-term survivors. Of 10 patients with delayed onset of shock, the condition of only 4 improved, and none left the hospital alive. Myocardial rupture was proved to have occurred in 5 of these patients, and suspected on clinical grounds in 1 patient. The clinical management essential to successful intraaortic balloon pumping is summarized.     

Intraaortic balloon pumping as the postangioplasty strategy in acute myocardial infarction.

To assess the usefulness of intraaortic balloon pumping (IABP) in acute myocardial infarction (AMI), 114 patients with anterior AMI undergoing emergency percutaneous transluminal coronary angioplasty (PTCA) for total occlusion of the left anterior descending artery were studied. After successful PTCA 66 patients were treated with conventional therapy (group I), and 48 patients were treated with IABP for 25 +/- 8 hours (group II). The reocclusion rate was significantly lower in group II (2.4% vs 17.7% p less than 0.05). An increase in ejection fraction in group II compared with group I was marginally significant (4.5 +/- 12.2% vs 9.2 +/- 13.0%, p = 0.08). Vascular complications occurred in two patients, but there were no deaths from IABP. These results suggest that after successful PTCA for acute myocardial infarction, IABP prevents reocclusion and may add strength to reperfusion in the improvement of left ventricular function.     

Unfortunate outcome of subsequent vascular complications in female patients assigned to percutaneous coronary intervention -- case report

We present a case of a 58-year-old female who underwent elective PCI of the left anterior descending coronary artery. The procedure was complicated by vessel dissections and myocardial infarction. Cardiogenic shock complicated acute coronary syndrome required intraaortic balloon pumping what led to descending aortic dissection successfully treated with stent-graft implantation. However, the patient died due to intractable cardiogenic shock.     

The in-hospital development of cardiogenic shock after myocardial infarction: incidence, predictors of occurrence, outcome and prognostic factors. The MILIS Study Group

The incidence, outcome and predictors of the in-hospital development of cardiogenic shock and its prognostic significance were analyzed in 845 patients presenting with acute myocardial infarction. Cardiogenic shock developed after hospitalization in 60 patients (7.1%). In half of these patients, cardiogenic shock developed at least 24 h after hospital admission. The in-hospital mortality rate was greater than 15 times higher for patients with cardiogenic shock than for patients without shock (65.0% versus 4.3%, respectively, p less than 0.001). Enzymatic evidence of infarct extension occurred in 23.3% of the patients with shock compared with 7.4% of those without shock (p less than 0.0001). Multivariate analysis indicated that independent predictors for the in-hospital development of cardiogenic shock were age greater than 65 years (p = 0.007), left ventricular ejection fraction on hospital admission less than 35% (p = 0.007), large infarct as estimated from serial enzyme determinations (that is, peak creatine kinase-MB isoenzyme greater than 160 IU/liter (p = 0.008), history of diabetes mellitus (p = 0.011) and previous myocardial infarction (p = 0.012). Patients with three, four or five of these risk factors had a 17.9%, 33.7% or 54.4% probability, respectively, of developing cardiogenic shock after hospital admission. Left ventricular function, as reflected by left ventricular ejection fraction (p = 0.04) and severity of left ventricular wall motion abnormality (p = 0.04), was the most important determinant of in-hospital mortality in the patients with cardiogenic shock.     

Effects of intraaortic balloon pumping on coronary hemodynamics after coronary angioplasty in patients with acute myocardial infarction.

It has been reported that intraaortic balloon pumping can prevent reocclusion after coronary angioplasty for acute myocardial infarction. The speculated mechanism has been the production of markedly enhanced diastolic coronary perfusion pressure; however, most studies have reported that intraaortic balloon pumping has little effect on coronary blood flow. To assess the effectiveness of this procedure, we studied 12 patients with acute anterior myocardial infarction who were undergoing coronary angioplasty and intraaortic balloon pumping. After successful angioplasty, coronary blood flow velocity was measured with a coronary Doppler catheter before and during intraaortic balloon pumping. Although mean coronary blood flow velocity was unchanged, intraaortic balloon pumping increased peak coronary blood flow velocity from 34.6 +/- 5.0 cm/sec (mean +/- SEM) to 46.7 +/- 5.8 cm/sec (p < 0.005). Such an increase in peak coronary blood flow velocity seemed to be a mechanism by which intraaortic balloon pumping could prevent reocclusion after coronary angioplasty for acute myocardial infarction.     

Efficacy of percutaneous transluminal coronary angioplasty in patients with acute myocardial infarction complicated by cardiogenic shock.

Cardiogenic shock still remains a highly lethal complication of acute myocardial infarction (AMI). This study reviews our hospital experience in treating AMI complicated by cardiogenic shock to evaluate whether coronary angioplasty improves survival or not. We have treated 523 AMI patients from 1985 to 1990, and among these, 26 patients with AMI complicated by cardiogenic shock who underwent percutaneous transluminal coronary angioplasty (PTCA) compose the study group. In 16 patients, PTCA was successful (Groups S) and in 10 patients, unsuccessful (Group F). There were no statistical differences between the Groups with respect to clinical background, intraaortic balloon counterpulsation (IABP) or emergency coronary bypass graft surgery. Before PTCA, hemodynamic variables including cardiac index, pulmonary capillary wedge pressure and systolic blood pressure were similar in the 2 groups. After PTCA, cardiac index in Group S patients was better than in Group F patients (2.18 +/- 0.61 versus 1.62 +/- 0.65, p less than 0.05). Thirty day and 1 year survivals were also better in Group S than in Group F (30 day survival: Group S 56.2%, Group F 10%, 1 year survival: Group S 31.2%, Group F 0%, p less than 0.05). Multivariate analysis showed that age under 75 years old, systolic blood pressure over 90 mmHg after PTCA and successful PTCA were independent predictors of 30 day survival (p less than 0.05). It was suggested that PTCA was an effective procedure to reduce mortality in patients with cardiogenic shock.     

Intra-aortic balloon pumping and variations in flow in the dilated coronary artery in acute myocardial infarction

The object of this study of acute anterior myocardial infarction uncomplicated by cardiogenic shock, a context in which the role of intra-aortic balloon pumping (IABP) remains controversial, was to analyse the effects of IABP on coronary flow in the culprit artery. Twenty-one patients admitted for angioplasty in the acute phase of anterior myocardial infarction were included. The IABP was performed in 6 patients (Group 1) because of clinical signs of cardiac failure. Fifteen patients (Group 2) had no signs of cardiac failure. Coronary flow velocity was recorded by a Doppler catheter after successful angioplasty. The following parameters were analysed: average peak velocity (APV), average diastolic peak velocity (ADPV), average systolic peak velocity (ASPV), diastolic to systolic velocity ratio (DSVR) and maximum peak velocity (MPV). Intra-aortic balloon pumping was associated with an increase in the diastolic indices (APV 17.9 +/- 3.5 vs 14.9 +/- 3.6 cm/s; p < 0.05; ADPV 27.6 +/- 5.2 vs 19.7 +/- 4.7 cm/s; p < 0.05), and a decrease in the systolic index ASVP (3.8 +/- 1.3 vs 7.6 +/- 2.6 cm/s; p < 0.05). The diastolic indices recorded with IABP did not change in Group 2. The velocity spectra changed with the appearance of abnormalities usually described in the presence of microcirculatory abnormalities ("no reflex" phenomenon): decrease in anterograde systolic flow, rapid deceleration of diastolic velocities with appearance of a retrograde systolic flow. The authors conclude that IABP increases diastolic velocities of coronary flow in the acute phase of revascularised anterior myocardial infarction complicated by left ventricular failure but does not seem to be accompanied by improved myocardial perfusion.     

Primary angioplasty for cardiogenic shock complicating acute myocardial infarction.

To evaluate the role of primary percutaneous transluminal coronary angioplasty in cardiogenic shock, 53 patients admitted with the diagnosis of acute myocardial infarction and cardiogenic shock were studied. Thirty-five (66.0%) patients received intravenous thrombolytic therapy (streptokinase 15 lac units) and 18 (34.0%) underwent primary percutaneous transluminal coronary angioplasty. There was no significant difference in the mean age, risk factor profile, presence of prior myocardial infarction, site of myocardial infarction and cardiac enzyme levels at presentation between the two groups. More male patients were present in the group undergoing primary percutaneous transluminal coronary angioplasty (94.44% vs 68.57%; p = 0.04). The time delay between the onset of symptoms and presentation to the hospital did not differ significantly between the two groups (318.9 vs 320.0 minutes; p = NS). In the primary percutaneous transluminal coronary angioplasty group, 17 patients had a single infarct-related artery and one had both left anterior descending and right coronary artery occlusion. Thus in 18 patients, 19 vessels were attempted. Angiographic success (< 50% residual stenosis) was achieved in 15 (78.94%) vessels of which TIMI III flow was achieved in 10 (52.63%) vessels and TIMI II flow in five (26.31%). Intra-aortic balloon pump was needed in five (27.77%) patients undergoing coronary angioplasty. In-hospital mortality was 27.77 percent in patients undergoing primary percutaneous transluminal coronary angioplasty and 57.14 percent in patients receiving intravenous thrombolytic therapy (p = 0.04). In the thrombolytic therapy group, mortality was higher (85.91%) in patients presenting six hours or later after the onset of symptoms as compared to those presenting in less than six hours of the onset of symptoms (50%). In primary percutaneous transluminal coronary angioplasty group, mortality was 21.42 percent in patients with successful and 50 percent in patients with failed angioplasty. Thus, in patients with acute myocardial infarction and cardiogenic shock, an aggressive invasive strategy with primary percutaneous transluminal coronary angioplasty, as compared to intravenous thrombolytic therapy, is helpful in reducing in-hospital mortality.